I know we have camps here on whether our current lens resolutions are adquate to meet 40+ MP.
Some of the superteles that were recently redesigned were done with that thought at the forefront of their mind and will do well with the higher resolution sensors. More recent version "II" zooms including the 24-70 II and 70-200 II ... will be fine.
I am not so sure about some of the older legacy L's, let alone consumer EF's.
I am not saying every single one of the older lenses lag behind, I think most do. I think 135L will be fine, but certainly 35L, 50L, and sadly perhaps even the somewhat recent 24L II will not fare so well on high MP sensors.
So it is good to see the acknowledgement in the CR post (if it is truly from Canon) that some of their lenses will have to be updated to meet the high MP sensor demands.
Again, I know some feel most key lenses out-resolve planned sensors... I feel only on paper is such a contention true. Canon will quietly start upgrading their key primes...35L II and some form of 50mm are probably imminent.