IIRC her prohibition on Keltiad fan-neepery extended to disallowing fan websites, even strictly canon-based informational compilations. But I could be wrong.

I don't think it's so much the names she's protective of-- a fair number of them are taken from Celtic lore (Taliesin, Arthur, Padraig), and exactly how does one copyright Saints Brendan and Brigid as fictional characters anyway?-- as the characters and contexts she's built behind them. If she's decided that she'd rather let the Keltiverse entirely disappear rather than be touched by other hands, however superficial/transitory those touches might seem to a third party, then that's all there is to it, I guess.