The requests for ship interiors show it's popular as ever. For example on the ED subreddit:
A real discussion: what would adding ship interiors look like to you? - 2 Nov 2024 - 66 upvotes, 122 comments in 13 hours.
Requests to make aspects of the game open only are also hugely popular... with certain portions of the community.
Requests to add many features to the game will always be hugely popular. A thread asking FD for atmospheric landings would be hugely popular. A thread asking for on-foot Thargoids would be hugely popular.
Its always a question of resources and viability, and of course, the developers willingness to do it.
As noted on this page, a comment from a dev about adding interiors to crashed/landed ships would be doable with the game's current state. This is because they wouldn't use the current ship models or require any extra coding. Just new assets of unmovable ships (eg: crashed Anaconda), like buildings that you can enter.
The tricky part with ship interiors is handling the physics of moving objects and disconnecting the player and NPCs from the ship. When you enter a ship, you are not your character. You are the ship. Moving around inside a moving object adds a lot of complexity.
Not saying FD can't do it. They already do it with station interiors. I guess they use the same trick i've suggested for ship interiors myself. When you enter the station its a fade to black and you are actually on a different "map" from the exterior. When you look through the window in the bar, you're not actually in the same space, the same "map", you're looking through a kind of portal to the other "map", so your character isn't actually rotating with the station, just the camera view is.
So, maybe they could do ship interiors in the same way. You fade to black to the interior, and there you aren't actually in the same space as the exterior, just a separate map you can walk around and the windows show the other map. This would require a rework of the engine to handle that for spaceships of course, especially flight.
Another way, in which they interior is in the same space as the exterior, is only allow walking around when landed. As soon as you sit in the pilot seat to move, then fade to black for everyone, evereyone is put in seats (or kicked off the ship if more people than seats) and then its back to the old model for the flight. On stations, you can only stand up once in the hangar and therefore in the fixed map space.
Or they could go the Star Citizen route, but that is a lot more work and lot more bug prone, which you will have seen if you've watched videos of people moving around in moving spaceships and getting ejected into space and clipping through floors and whatnot. I don't think FD can afford to try that route.
The big question for FD would be "is it worth it?" If its just so people can walk around the interiors, i think the conclusion has to be no. Its a lot of effort for effectively zero added gameplay. If it comes with some interesting mechanics, then the answer might be its worth it. But that depends on the approach. For example, ship to ship boarding and EVA and stuff only would be possible with the fade to black entry/exit and separate map variant of the first option.