You could, because refurb gear comes at a significant price reduction and the firmware is usually updated - you are sitting on the sharp part of a fence between wanting a cheap deal, but not wanting grey market.
Canon have made it clear that their priority is now their R-series cameras and with production issues including shortages for things as universal to multiple bodies as screws, a lot of products are being held up. So, you may wait quite a while and when they do come to stores, you can join a queue of other 90D hopefuls hoping for a deal when it is a seller's market...
As to firmware, that is a fairly straightforward process and it's something to get used to as Canon is doing more firmware updates these days than it had previously done.
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
