We are talking about a people that went so far down the mad scientist road that their knowledge not only obliterted them but allowed them to turn the snow elves into horrible blind malformed canabals.. I'd rather have the Nerevarine do a cameo personaly.

I dont really understand the 'its their lore and they can do what they want'.

The first part is correct, the latter absolutely not.
Just because you think up something doesnt mean you can do what you want. Not if youre in the business of selling people what you think up.
It will have to follow the rules of balance and gravity when you are creating a marble sculpture.
If it doesnt, it will just crumble apart or fall off its feet. You have to follow the rules of esthetics or originality if you want to sell it.

You most certainly cant do whatever you want.
The good people of Sesame Street cannot turn Ernie into a muppet-killing terminator.
Transformers cant have Optimus Prime transforming into a Care Bear and carebearstaring Megatron away.

You cant have people come back from the dead for no reason, you have to follow the rules of good storytelling. The story has to be internally consistent. You have to be true to your genre.

The Dwemer cannot not 'just' come back because they removed themselves from Creation. They became a big giant stompy robot, and that has exploded into a million pieces.
They cannot come back without forever destroying the beauty of their story, which explains so much about the purpose and function of the Mundus and they cannot come back without forever destroying their mystery.

Mystery is far more interesting than any explanation can ever be.
The Dwemer should stay gone.

This! My toughts exactly

I'd be excited as hell if they brough back the Dwemer as the storylines you could make with them could be endless.

I'd only ever want to see them return as the enemy. A physically weak race dressed in robes and far from warrior status who hide behind machines of mass destruction.

Can the Dwemer return? Yes.
Should the Dwemer return? No.

I think the only way they can make an appearance is by some divine breaking. We would need to break the Time Dragon or Walk-Brass, or something. . . I don't buy the idea that once they are gone, they are gone for good.

Does Numidium still have its skin? The Dwemer still exist as the skin of Numidium, IIRC. There is no reason why the transformation of Dwemer into divine flesh has to be a one way trip, IMO.

I think a game would have to be epic enough for the protagonist to rebuild Numidium, and then rip the flesh from it. I don't know if this would cause a "Brass Break" or not, but it would be epic.