Be careful! Three years ago I almost got run out of town for saying this would happen within five years.
And I never said it would be suddenly, like the prices going over a cliff. But it freaks people out who are holding EF glass, especially L glass, and who are sitting on the fence. (And that's why I started posting my concerns, because I had a brief panic, but fortunately the great majority of members here patiently put me at ease. Then I felt even better when I finally got my hands on an R and fell in love with Canon mirrorless.)
I still have a few EF lenses. The ef 35mm f/1.4L II, the 135mm f/2, and the ef 100mm L macro, which all work nicely on the Rf mount; and the original 70-200mm f/4, which I'm keeping for the 80D my kids will soon learn how to use. Plus I have an ef-s 24mm pancake for them. I don't plan to sell any of these, just use them until they can't be used anymore.