As long as there are EF and EF-S cameras being made there will be EF lenses. We have people here who are still using film EOS cameras. The installed base of EOS DLSR's is *huge* and will not go away soon.
There is not a mirrorless yet that offers the performance of a Canon 1 series so don't expect the EF lenses to disappear soon. Canon just introduced a newer version of their excellent 400 F2.8 EF that I will be acquiring shortly. I will be obsolete ...
