If we see a 50+ MP sensor in a Canon professional camera it will be interesting to see how older lenses still in manufacture hold-up. Higher resolution lenses properly corrected for chromatic abberations & color fringing will be expensive to make, so expensive that for many they will not be affordable its not just the glass but the mechanical tolerance to make that glass work optimally all the time.
This is no more pixel density than the 70D, and even an 18-135STM holds up quite well on that camera. So, any lens with quality equal to or better than a relatively cheap but decent consumer hyperzoom will hold up just fine. Now, the 18-135 is an EF-s so that makes it easier to design and cheaper, but the same thing should hold for lenses like the 24-105STM. Lenses like the 16-35IS, 24-70II, 70-200II, 100-400II and basically all the L-primes and decent consumer primes (24/28/35/85/100) will be just great.