Jabs make you escape to the ground ONLY if you were gonna be released at that time anyways.
For example, get Wario to 100-150%. Grab Wario with Marth, Snake, etc. Do 2-3 grab jabs with the Wario trying to escape (not rotating the control stick 1000x per second, but still trying to break free) and then stop jabbing. Wario will be released into the air, even though you hit him with a few jabs.
Now try doing that at a lower % and have the Wario go berserk on his controller while you get in 2-3 hits. If you are about to hit him/hit him when he breaks free, he will go to the ground.
Just clarifying that in case people start to think Jabs will always make Wario go to the ground no matter what. They will only make you go to the ground if you are hit/close to being hit by the Jab when you are released. Yoshi is oddly a weird exception, he always spits you into the air
![Frown :( :(](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)