There is a lot of click-bait on this subject, and it has been hyped up massively. Canon have not stopped 3rd party manufacturers; they have held back licensing for creating 3rd party RF autofocus lenses for the time being. That has not been helped by Canon's rather muted response to the whole issue. It is important to separate what we know from the hype here.
What we know is that two lens makers have been given a cease-and-desist instruction from Canon for impinging upon their patented R autofocus lens features. In that respect Canon are perfectly correct and within their legal and ethical rights. Actually, they could have been far more hostile and sued, but they didn't. One of those makers, Viltrox, have published a statement to that effect and it was confirmed by a brief comment by Canon Germany. I suspect that it is likely Viltrox did not actually reverse engineer Canon's IP but may have had access to it through licensing and then jumped the gun in releasing it before they should. This is, to some degree, supported by the Viltrox statement that for the time being, these lenses are no longer offered. If they had reverse engineered, they would almost certainly be required to delete any IP and the results from that.
What we don't know: What will happen in the future, but there are clues that one can assemble and they are worth exploring...
Historical Context: Back in the 90's I was around when Canon changed from the FD to the EF mount for their new range or EOS systems. 3rd party companies like Tamron had been producing mounts for makers - I had their lenses for my Nikon and Canon gear for about 12 years. When the EF mount came out there was a delay between that being released and 3rd party lenses coming to market, and an article at the time explained why.
Canon wanted to establish its brand as reliable and was still doing work to perfect the firmware in a controlled manner. There are issues with autofocus and focus tracking at the moment that are being addressed, so it's still a work in progress. Outsourcing that tech as is to 3rd parties was not considered a good idea for anyone, and then there was the obvious business decision to allow some time for EF lenses to be sold. Given the millions Canon have invested in the mount and lenses for them, that is not unreasonable nor unique to them. However, that period was relatively brief as a lot of lenses came on market from Canon in quick succession.
Now fast forward to Canon's release of the RF mount in 2019. It was definitely late to the MILC market and had to get some bodies out there, so it released the rather tepid R and RP bodies, along with a few lenses. Then something completely unplanned happened. COVID hit.
The impact was massive across the world and across many industries, especially those relying on Chinese manufacture - and Canon was one of those. There were reports of empty factories, and closed production lines for lack of staff, lack of raw materials and as simple things as screws, without which parts could not be assembled. Because different manufacturers got their components from different sources, they were impacted in different ways. That disruption is still being felt and it has had two impacts on Canon's processes.
The design and development of new lenses and significant disruption to supplies for production. We are seeing the same thing with the Nikon Z9, for example with massive backlogs of orders, so this is not unique to Canon.
Canon should have got more lenses out and would likely now be in a position to license their IP to other makers, but they are likely not - their lens road map is still not fully developed. They have done great work via their adapters to allow legacy native and 3rd party lenses to work well with Canon R-series bodies, but the native R lenses are lagging, especially in the lower price bracket. Things have got more complicated as people clamoured for more bodies, APS-C bodies and lenses to match - the market they have to fill has expanded significantly.
However, 3rd party suppliers have also been impacted and the bigger names are likely also stressed for resources for both development and production for the same reasons.
Canon aren't stupid, they know that having 3rd party glass will enhance their market for those who, for one reason or another, do not use native Canon glass, so it's actually to their advantage to let that market develop. Sigma and Tamron have signalled that they will be developing glass 'in due course'. I doubt that they will say that and risk criticism if that was not a practical possibility.
So, instead of committing to statements about abandoning Canon, or whatever, I am merely saying that there are many more factors to consider than the ones being touted to make Canon into a villain. Canon is a business entity, and it is pragmatic in engaging with trusted suppliers. However, given their behaviour, Viltrox may not be on the immediate list for early licensing. I note that they are still selling EF and EF-M glass with no issues, and they have said they are stopping production of RF glass for the time being.
Further, I strongly recommend the video of an interview with Sigma CEO Kazuto Yamaki at his new facilities: HERE - he seems to be an awesome guy and has a great ethic for his product and his employees. It is interesting to note that one of the reasons for his major facility expansion was the hiring of significant numbers of engineers " for the new camera mounts". There are (to my knowledge) only two new mounts at present: Canon and Nikon, so that suggests to me that if they are confident enough to invest in new capacity for this, then they must believe that what they produce will come to market. Further, Sigma as an old business partner of Canon, is extremely unlikely to try to reverse-engineer anyone else's technology, so it suggests that they have a connection to at least some of Canon RF IP.
So, be patient - this situation is very, very new and let's wait until the dust settles.
cheers, TREVOR
The mark of good photographer is less what they hold in their hand, it's more what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
