One has absolutely no connection with another. It's been 13 years since BioWare last used Origins' engine. Few people in software development stay in one company for that long (especially programmers who would feel no personal connection to company's IP, unlike writers or artists).

The game sucks because of the writing not because it runs on a different engine

Does it suck tho, or are gAmErS just whining because trans people exist in the game? Can never tell nowadays.

Dragon Age: Origins came out 15 years ago. That's a very long time to stay with the same company in the tech sector. It's not at all unusual that there are so few people left who worked with the engine for the first game.

They are probably an experienced team members that are needed on ME5, and management decided that they can't distract them. And these new devs would spend a lot of time figuring out a completely unfamiliar codebase (also creating a proper remaster would also necessitate a lot of low-level changes to the engine which will make it much harder). So it's a business decision, not technical one.