I wonder why it's not more common to open source abandonware that has exactly zero remaining commercial value. These game companies don't even have to remain as maintainers/stewards of the code. It doesn't even have to compile. Just release it, and many people will get it to work! How much expense could it be to get an intern to upload the code to GitHub, slap a license on it, and never look at it again?
I'm a big fan and played WFTO quite a bit at to the point it's hard to go back to DK2. Sadly their AI got much worse with the 2.0 patch and I gave it up.
There is a Dungeon Keeper 1 remake https://dungeonkeeper.fandom.com/wiki/Dungeon_Keeper_FX which similar to lots of these efforts uses the original artwork and sounds.
There are some other DK clones and descendants, but my second favorite would be the very late Dwelvers https://dwelvers.com/ which has been in development for an eternity and the developer shows up once or twice a year with an update. This is the most ambitious of the DK clones as it includes a much larger economy and even the long promised above ground!
If it's actually abandoned, then there's probably nobody around who can do that.
Otherwise, what's the incentive? And there's always someone who thinks they can milk the title by selling it in a retro bundle or a cheap remastered edition. Of course, these days you don't even need a remake to milk old titles.
https://www.gog.com/game/dungeon_keeper_2