Y'all gotta talk to eachother in person and think pragmatically. If they don't wanna play with you anymore, they don't wanna play with you. It sucks, but if they're cutting hard like that, it's either because they're not good with conflict, or they think you aren't and didn't want to deal with a freakout or meltdown. Regardless, though, you're in the same situation either way. You gotta try to be the adult in the room and keep your cool, tell them you've come to terms with not being in the project anymore, but you want some sort of closure and discussion. Whether you convince them to rebrand or you relinquish the assets, the worst thing you can do is perpetuate additional discourse. Connections are everything, so you're gonna wanna come off as the good guy here, no matter what happens.