>>43028334A bit hard to tell, but most likely, it would've been.
On one hand, he was infinitely more requested and almost expected, so there would've been a larger and happier fanbase. Also, you would also please those MUH STARTER TYPE TRIO! autists and admittedly finally give the Grassfags a bone by lending them their very own Great Value Greninja.
On the other hand, Incineroar brought a more refreshing playstyle to Smash instead of yet another zoner, so at least it has that going for it. I think Decidueye would've been a bit boring to play, which is not a great argument as Sakurai can make anything marginally fun to play at the very least, but i still don't think it would've been funner than Incineroar. Although on the OTHER, OTHER hand, Heavies are mostly shit with the exception of Snake, ROB and Bowser, and Incineroar is no exception. I'm the only one i know that plays him because most braindead heavy mains gravitate towards Ganondorf instead. He also doesn't get tourney play despite his recency. If Decidueye were a slow zoner i think it would get even less play than what Incineroar is getting right now, but realistically, a pseudo-Link with a projectile that can Spike/Bury would be at the very least Mid Tier
TL;DR: Decidueye would've had a warmer reception, but chances are that either choice would end up fading into irrelevancy in the long run
