The comments have almost no quantitative evidence and are therefore of little value. Videos are a much better source of evidence of push but it can be hard sometimes to draw conclusions from what you see.
I haven't seen anything in the videos you've posted so far that display pushing that would be inconsistent with P99 push. The Trakanon, Maestro, Inny, Cazic, and Gorenaire videos do show gradual push that is about what I would expect with the mobs being surrounded and attacked from all sides. The push on Gore is slower due to her melee slow ability, but it's still there when you see her "teleport" from one spot to the next as she's being attacked. Zlandicar starts off by fearing and stunning the raid, but once the fear wears off and everyone moves back into position you can see Zland get pushed into the wall in seconds by keeping an eye on the rate his wings clip into the back wall.
Here's a clear example of a mob being pushed very quickly by a raid force that coordinates their push in the same direction. This video was taken by the same player who did the Trakanon video you posted, recorded during the Luclin era. Watch Vindi get pushed around like a motherfucker:
https://youtu.be/cpaqYUqel1A?t=43s
In classic raids the players didn't really see a need to push mobs large distances in a coordinated fashion. Classic players did not have years and years to farm items and get max haste and were worse geared on average than current P99 players. The best explanation of why you don't see much mob push in classic videos is some combination of these two reasons: they just weren't trying and they were attacking slower and therefore pushing less.