Generally speaking this is another quality of life feature that I could see being useful. For folks missing achievements, gear and such its great. I can’t see many XR-raids being regularly successful in the current content, but might be for older raids. Like Nef, BWD, etc.
Hopefully it can be used for all previous raid content, not just the current expansion. Sunwell, BWL, AQ, etc all will be useful to run again – especially as people will be looking for gearsets.
Goal: cross-faction, real-id, and cross-realm, for both raids and dungeons.
Basically let us group up for anything, with anyone, and set some simple rules in place to make a forced balance, just like the LFD tool now. I see no reason to not allow cross-faction for runs, except that some look is faction specific. That is solvable via a rule that says the faction of the leader is dominant, and offer a vendor to switch it over if you get the incorrect faction loot.