iMovie imports the unedited version of photos
I just created 3 iMovies using a series of photos i had previously edited in Photos. IMovie imported some photos in the edited state and others in the unedited state, even within a single timeline.
The importing of Photos into iMovie where the edits don't carry over appears to be a bug that started from Monterey forward. It happens when one attempts to import into iMovie from the Photos item in the iMovie media sidebar Others have complained about it. We'll have to wait for Apple to cure it.
Meanwhile, a workaround is to do a File>Export>__ no. of photos from the Photos app to the desktop, and drag the photos from there into iMovie. The edits will carry over.
I believe also that you can open iMovie and the Photos app library side by side and drag the edited photos directly into iMovie. I'm not running Monterey or later, so cannot personally verify that. It works with Catalina.
-- Rich