I get it... to get there u need to call a dragon , trap him and ride on its back but why cant we get back there ?
I also get that would make a problem cos trapping him was one time event in game.
Why wont u change that in patch that u can summon that dragon again in place like throat of the world ? Its neutral place so that wont be that much work... for example fixing bugs with npc reactions for a dragon... like guards or something in the city.
In interviews i saw bethesda employees claiming that quest in games be like " u killed quest giver ? ull get that quest from his/her brother or ...start it with an item u found " and i very liked that concept.
Yet we cant get back to Skuldafn :/
for me personally that screws fun cos i want Nahkriin's mask and i think i might left it there.
of course i killed that dragonpriest and looted , still cant find it in my inventory so i probably left it there