I noticed

Aren't you one for getting to know the lore/history of Fallout - this could be your chance to witness firsthand how the days of House and Vegas unfolded. Like I said though my idea would be to shadow him and explore the city but you can't actually impact that world by talking to people or sticking out a ghostly foot to trip up House as he runs to his machine. It would simple be a - "Oh that explains --" kind of scenario giving loads of info on Pre-War Vegas and how/why it's still alive today.

- Effectively on a large scope it is pointless but it's something better than nothing.

It's not lore I'd really care for.
For example, if there is a small piece of lore up in a mountain that is very isolated then it might be a nice bit of lore, it might be an amazing bit of lore, but it's an isolated bit of lore.
Pre-war Vegas would be that isolated bit of lore that no longer serves any purpose in the new world.
It might be great, but it's not important, not to me at least.


Cause while it'll show off House and the Strip, both have undergone changes since the last 204 years, even if we got a peek at the past it wouldn't clash with the Vegas of today.

Not really.

Part of the Fallout experience is seeing the ruins of what's left and then trying to picture 'the way it was' and what was lost. To put a flashback section in the game kinda ruins that wistful faux-reminiscence.
Not to mention, the simulation would be limited by the same limits the main game has, and therefore the past it show me would be too big, too empty of NPCs and too blocky. I'd prefer to imagine a 'perfect' version then to have to see a mocked up one.

For me, the odd note on a PC screen or sound clip from a tape does 1000x more to portray the feeling of loss than a little ‘simulation’ sequence could.