Bloom can be turned off confirmed by Sega Europe
https://twitter.com/SEGA_Europe/status/1014616351229370368 Good news. I think I’ll keep it, personally! At least for my first play through. I don’t know why anyone would want cropped, zoomed in cutscenes; that sounds terrible lol.
I don't mind Shenmue 1 sticking to 4:3 but Shenmue 2 cutscenes are letter boxed so it would make a lot of sense to zoom them in. 4:3+letterboxing is just going to make them look really small

Blue haired clown has been fixed, I repeat, blue haired clown has been fixed!(Screenshot from the new Return to Dobuita Street video)

Yeah, it will definitely be because of the game's having dual audio that will add things up a lot, plus Shenmue II's cast size being bigger than Shenmue I's as well (more NPCs + more voiceovers = more GB). Pretty sure Shenmue II just has more cutscenes as well.
If its just Japanese voices wouldn't the Shenmue 1 be double the size as well? Yes Shenmue 2 has a lot more audio I know.

Point Im making is dual language isn't going to magically make the game an entire 5gb larger. It wouldn't even make it 4gb larger because you're ignoring the space taken by the actual game assets.

Its all speculation right now I guess but there's clearly something more happening to add an extra 5gb