This was the most diTerlizzi-esque thing I could manage with my afternoon's experience with MidJourney:
View attachment 260098
I don't know if it filters out requests for the style of specific living artists, or if it just couldn't find enough of his art to get the style. But since I feel his planescape art has obvious Arthur Rackham influence I specified that instead, and just requested the most DiTerlizzi of all subjects, an elf girl relaxing in skimpy armor.
But fantasy artists aren't going out of business anytime soon. AI art can, after a few tries manage art of human (and human adjacent) subjects in a fantasy setting, albeit usually with some complications about items carried by them which it really can't figure out the rules for (the objects this lady had in her lap make no sense). An artist skilled enough to do touch-ups and corrections could get a lot of mileage out of it for such things. BUT even the most basic of fantasy creatures are too varied in the representations it's searching through to get satisfying output (although I think the output is very useful for brainstorming or creating rough versions to be redone by a proper artist). It just can't figure out the rules for things that only exist in people's imaginations, which is a huge part of what is needed for D&D books.
Behold, the results of my attempt to use similar means as those I used above to create a picture of a dragon flying over a fantasy city (these were some of the better results):
View attachment 260099