Firstly, it's not Wikipedia, it's Wiki.
Secondly, your perspective is proving to be rather narrow, Stir, seeing as you still don't get it after two attempts.
Welsh first showed up in KOTOS Stories in the Rhoddwr Marwolaeth, which title is in itself Welsh and thus the first occurrence of using the language in our stories. Specifically, it was Thingguy2 one of the two co-writers of the story who introduced Welsh into the story, possibly because he knew the language himself. Examples of Welsh or modified Welsh include Lord Enfawr, Darneu (derived from Darnau meaning pieces) and possibly Haedelra.
The Rhoddwr Marwolaeth has left behind its legacy by inspiring more KOTOS writers to use Welsh in their naming schemes in later stories, especially the Additional Manuscripts. Examples include Odcysgod, Twrserendydd (from the Adventures of the Peculiar Enchanter) and Mynydd Tiwna (from the 'To' Series). In fact, the influence of Welsh even inspired the creation of the ancient people called the Kelters based on the Welsh and generally Celts.
This could be a (succint) example of what could be written in such a page. I don't find it impossible or nonsensical that such a page could exist.