I can imagine that, yes, because it’s pretty standard in an awful lot of publishing as well.
Yup. There are an awful lot of Star Trek/Star Wars/Warhammer/etc novels out there, and no one's getting a rights deal on those. For all that you can criticise work-for-hire* it has the advantage that you get paid to
just write (or draw).
There's a lot of peripheral stuff involved in either self-publishing or going creator-owned with someone like Image — a huge amount of hustle and promotion is required, unless you already have heavy name-recognition in your chosen market, or there's a real chance that you'll make next to nothing.
* And I've said, repeatedly, that it shouldn't be beyond the wit of man to devise a contract that safeguards the publisher's investment but is more equitable to the creator(s). Publishers who insist on work-for-hire could offer a
very modest percentage of secondary exploitation (foreign language editions, movies, TV, computer games, merchandise) it would probably be enough for the vast majority of creators.