Considering how many times ProfitUI has been resurrected, and considering it is all based on the work of the EverQuest II team, I would be shocked if there was an enforceable copyright. I see no reason to worry about that, but plenty of reason to worry about the future of ProfitUI. Just look at the ProfitUI forum. It's chaos. There's no link to download the current ProfitUI.
There is a smattering of updates for ProfitUI Reborn in these two threads, but no unified download package or continuously updated thread with the latest information. The way it is now, ProfitUI is just dying on the vine. Something you have to cobble together and read 50 threads to keep running means only diehards will mess with it.