FICTION, I got news.
The combo that Ally did on M2K with Wario DThrow Tire > Uair > DThrow Tire > Uair, is not a true combo against MK, it's just a really good combo but it can be Airdodged OUT if you frame perfect it, and I assume you can Dair out of it also BUT it's seems impossible to a human being after trying for about 40 times I landed around 20 on my brother I missed 10 times the combo and he Airdodge'd out of it 10 times, by the way, the footstool WORKS the jump just come out too fast to MK react, tested with lvl 9 CPUS and my brother at home.
You can Dthrow > Uair > Dair, but the Dair WON'T pick up the tire which is bad to continue the combo, also I tried to DThrow tire > uair > ShortGlidetoss Fthrow tire > Fsmash, it does 54%. Dthrow > uair > Bite > Glidetoss FSmash works also but it's a LOT harder to execute.