Agreed, this is something on the "nice to have" list, not the "must be done" list. I do want this to be a thing, truly, but it's fine if we only get this 2-3 years after release (I'll be dead by then lol) as a big update.
I only watched a 2 min breakdown of the vid so I might be repeating things they already said.
For those who don't pay attention to these vijeos or just forgot, this has been a thing since forever.
The OG pitch from CR was that every building will have some sort of interior (obviously primitive, generated, not handmade) where missions can take place and we can hang out and the usual fever dream stuff...
Later when we got Lorville, nothing was said at first, like it wasn't ever a thing. But I distinctly remember that at the Area 18 release the topic got revisited. Then the pitch was that things like bounty missions will be generated as usual but those will temporarily generate an interior for the building the mission is played in, so the buildings won't just be empty boxes to get crashed into by the autopilot.
This didn't happen either.
Around this Citcon (2022) we got the word that Lorville will get an update. Great, who gives a f... anyways, the point is that we have seen the tools they use, the workflow for making the buildings and such. It's really simple and does NOT allow for interiors with the current exterior modules they use. And by current I mean the ones they spent at least half a year work on at this point for the updated Lorville!
The simple fact is that ALL non-enterable building modules will need to be reworked. Remodeled, retextured, adding real windows, real doors... a bunch of stuff. Also they will have to make a new clipping solution for the engine. Imagine having to load in and render ALL the buildings with interiors in Area 18 with windows you can see through! Yeah, that would crash even my system with 128gb ram.
Aaaand we haven't even gotten to the issue of floor level. What happens there? Can you walk out onto the streets? Then we will need roads! That's something that has been in the works for god knows how long, and the last time we heard about it was the one guy who did the river building demo mentioning that yeah, it's still a thing, using the same tech as the rivers, but nowhere near as usable as the river tool so it will be ages till it's done.
TLDR.: currently non of the assets support what they want to do with them, and neither does the engine. This is a great goal to have, on a long term basis. But not for 4.0, unless they already know that 4.0 won't be out for at least 3-5 more years.