Cavedog was accquired by Infogrames
You're right, sorry, Atari is just the brand name Infogrames use most of the time now. It's Infogrames which is the parent company and it's them who acquired Cavedog.
However the reality is Infograme never interested in any older games belonging to their brand or accquired companies, it's literally abandonware, but not actually law-safe tho.
Games don't become "literally abandonware" just because the companies who own the rights don't have an interest in it. In the same way that I can't come around and take your old car because "I haven't seen you drive it in ages."