That seems like a pretty good analysis. From what I've seen it's filtering down more and more as at my SR around 3300 i'm seeing these dive comps more and more. I think my team ran Winston, Dva, Moira, Genji, and Zen in 9/10 matches today... With only a sprinkling of other DPS getting the last spot and Mercy/Lucio replacing Moira once and Zen once each. Even on my gold account i see Winston/DVA all the time.
I think the problem is clearly the mobility of some heroes. Mobility kills in most competitive games. I don't see the guy really suggest this but i think they probably need to greatly up the cooldowns on Boosters, maybe nerf defense matrix also. But Boosters, Jump, Fade, and blink, maybe make genji a bit less mobile also. make the base speed boost from lucio like 15%.
I don't think you will ever be able to balance Heroes with the low CD/no CD movement abilities as they are.