Matriception:
The pilots releasing way before they even starts filming is a good way to give time to promote the show and check the interest of audience but maybe they don't need to do that now since gls have gained popularity, and personally don't see the point of pilots if they make the show inconsistent both time and visual vise.
My guess is because Idol Factory’s talent is very busy. Theyre all booked for a lot of things, so it’s better to go ahead and start filming if their schedules allows. They can still go back and refilm things or add scenes if pilot reception tells them to (scenes arent filmed in order anyways).
As far as promotion, like the pilot trailers are for, Idol Factory is also changing up the game by doing casting videos, casting announcements, workshop videos, etc. idol Factory also hit big with their first 2 dramas, and was the trailblazer for GL dramas, so i dont think funding is as big of a problem as it is for many of these BL/GL studios.