Yes, it does offer importing from Trello: In a “project” (i.e. a collection of boards), after clicking the plus-button to add a new board, you can either just give it a name and create an empty board, or your can click “import from Trello”. I haven’t tried it, though, I’m not a Trello user (because why should I; I have Planka, haha). You can probably try out the import capability with their demo instance.
Have fun with your self-hosting adventures!
The admins are probably ignorant sluts, I guess.