Actually this is not a new feature in hoyo games because honkai impact 3rd has implemented it for a long time, I don't know for ggz but it seems to be there too

I think this is for all the major cutscenes, I don’t think the smaller dialogue is recorded.

On PC: 13.2gb of video. 3.8gb of audio and 42.6gb of everything else. I wonder where 42.6gb comes from, maybe textures and animations

for this you dont need any extra size, just use same script like when running story and remove connection checkpoints, difference is game because it is not big open world with needing super distance view they can use higher quality textures on characters and objects when you compare clothing and faces on genshin characters here its minimaly 4-8x higher resolution, same for ingame cutscenes or effects plus there will be probably some garbage for upcoming updates

Are the cutscenes included? (The cinematic ones)

That's BS because the content is already there so it's just a decision to have place to replay it That would be stupid if the game was 2x the size because we have this Few reasons of why it's so big - all voice-overs are included in base download with translations - animations are higher quality with proper lip sync (just look at genshin basically non existent) - a lot of hand drawn assets Also could they implement 50MB chunk file size like in Genshin with direct download instead of unzipping or even better something like 4GB chunks