Space and time may be emergent, we don't know, all we do know is that our current model of physics is missing something. Quantum Gravity for example and We don't know what happens inside a black hole either.

That’s a non-answer though.

Do you mean they are guaranteed to discover another “realm” and move to it?

Why? It might not be possible, no matter how much physics one knows. Or do you take the Fermi paradox itself as a proof of the solution?

Yes, it seems that the Fermi paradox implies that other civs progress beyond what we consider signs of intelligent life. The great filter seems less likely as we get close to colonizing other planets, and then other solar systems.

I question your use of "implies" there. It implies no such thing. What you suggest is one possible answer, nothing more.

Yup, to me it implies a darker problem, that FLT is something that can't be surpassed. All civs might advance to that understanding and decide to maybe just occupy nearby solar systems and nothing more.

We may not talk to them simply because it's both incredibly expensive and will yield nothing more than "Yup, we're stuck here, so are you".

Why wouldn't they send out autonomous research/exploration vessels? At a sufficient tech stage it's trivial.

Sure, they could, but imagine they are 10,000 light years away. Such a craft would need to travel for a long time before it could communicate back it's findings.