Cloud can walljump, and he can wall-cling, but he can't walljump out of wall-cling. It's super weird >_> [Sheik can walljump, wallcling, and walljump out of wallcling, so it's not universal].
Easiest way if you have to walljump is to know in advance, airdodge into the wall, then press back to walljump at the right timing. Worked for me anyway.
Cloud seems to be able to auto-sweetspot up+b [aka Brawl/Smash 4 "snap"] on Pokémon Stadium. Not sure why.
Link's hookshot is weird [seems to cling to anything but no reel-in, just a walljump option, like they wanted to replicate Melee], and Samus has no zair at all. Sheik's chain is also ridiculously finicky with ledges. Were they trying to mostly remove tether recoveries, or...?