T-block
B2B TST
There are only 6 (as far as I know) matchups where the walkoff is broken. One of them, D3 vs. DK is basically unwinnable on any stage anyways, and another is D3 vs. Ganondorf. Yoshi, Falco, Pikachu... all the other CG characters can't make it far enough up the slope to kill. As far camping the blastzone, it's not effective here at all because of the upwards slope. If you camp there, you're above your opponent, which is already an inherently bad position.
"Stage floors that extend to blast zones" isn't a ban rule in any case. The criterion is whether a stage offers an overwhelming advantage to one or a small subset of characters such that any matchup against one of those characters is unwinnable. Super Mario Circuit was banned because of walkoffs because D3 could kill most of the cast with one grab. Yoshi's Island Pipes doesn't have any problem like that.
"Stage floors that extend to blast zones" isn't a ban rule in any case. The criterion is whether a stage offers an overwhelming advantage to one or a small subset of characters such that any matchup against one of those characters is unwinnable. Super Mario Circuit was banned because of walkoffs because D3 could kill most of the cast with one grab. Yoshi's Island Pipes doesn't have any problem like that.