But why? Just pick a new name and fork
They aren't stupid to abandon the brand and community just like that and start from nothing. The team plans to start a nonprofit that will work alongside and not under the current Manjaro company. They do say that if Manjaro GmbH & Co. KG declines, or the feel that they are dragging their heels (which they have done) they will start a strike. They are doing this rn. If that fails then they will just move to the next stage which is to leave and/or fork the project.
I just avoid the AUR on Manjaro whenever possible. It still works 99% of the time. The few things I actually need to be bleeding edge I will just try to build from source.