I mean, in order to hear Morgana you not only have to be in the Metaverse, but hear him talk too. but, then again morgana's voice rang out in shibuya, soooooooo

The way I understand it, the Morgana that appears afterwards only exists because the Phantom Thieves believe he does or some shit like that. Since the other characters don't know about Morgana then I'd assume he may not exist for them in the same way. Mostly just speculating as I don't remember the ending to the game too well anymore.

I think it's more of a "Only if you have the potential for a Persona" deal than a "If you can go into the Metaverse" deal.

Except Persona 5 doesn't really go into potential. Only the Persona 3 evoker method even mentions potential whereas Persona 4 seems to have no limits in regards to who can have a Persona as long as they face their shadow. As far as I recall Persona 5 doesn't mention who can and can't have a Persona at all.

I thought they made it a point that the user has to have a rebellious spirit, which is way you had to talk to everyone at the end. In p5. Or something.

Doesn't everyone at least have the potential to be rebellious though?

I guess your right, but wasn't that the point of the ending? Nobody wants to think for themselves so they submit to a god, so nobody wants to rebel because they don't care. Or something.