This too. People bring up the fact that they used beware the mushrooms as a big deal, but like Opposum mentioned licensing for advertisement and licensing for the actual game is different.I wouldn't personally use this as proof of any kind, only because these things can slip by in presentations when a different team who may not be familiar with ownership is involved. Also Opossum made a really good point in how it could potentially differ.
I will agree with WaxPython that music rights is a bit of a complex issue that deviates from contract to contract. (If thats what hes trying to say) There may be confusion as to who composed the music vs who owns it. The two aren't necessarily always the same or multiple parties could partially own it. Or how the contract is drawn could allow the original creator to use it for other projects specifically.
If square owns both the DQ music and SMRPG music 100% then yea they could be a little stingy, but at the end of the day it just means that Geno comes with 1-2 songs. Which I would assume most fans would take over the worst case scenario.
I mean Life Will change literally played in Joker's reveal trailer and has 0 presence in the actual game. I think Cloud in Smash 4 played Bombing Mission too, but that wasn't in the actual game either.
Playing Beware the Mushrooms doesn't really tell us anything in the long run and has no indication of copyright issues.