I mean, he is not wrong...chances are that with 3 charges, the CD will be so short that you'd not be able to dump 3 charges into one burst window, but maybe 4 or 5! :P
Maybe WAR will press more oGCD than DRK now! How the tables have turned...

I am personally fine with it being on charges instead of using gauge. But I think they should definitely find a way to avoid this "dump all charges in burst window" thingy. Especially for the gap closers, which should primarily be utility abilities.
IMO, charges are supposed to be a QoL improvement. But because the gap closers are dealing damage, it's not really what it is used for...

So, I believe that the problem is not that onslaught is now on charges. The problem is that gap closers deal damage. That's one of the reasons why the new Monk gap closer is a good change.
I don't know....just change the gap closers to only deal damage if you use them from far enough. That could work, especially now that they increased the range of the gap closers.

Tank gap closers are really just as weird design-wise as the new Scholar ability.