The Imperial Reach wrote:Canonically speaking we know for a fact that TLD had earned a spot in Sovngarde, and yet also - unwillingly - became the champion of Hermaeus Mora and like Miraak will thus be bound to Apocrypha.
No one else has a canonical claim on TLD's soul. For one thing, none of the other Daedric quests mention TLD being bound to those Daedra.
Being a Werewolf, Vampire, or Nightingale are the only other means by which to bypass defeat death destinations in the game yet because they are all optional it's unlikely that Hircine, Molag Bal, or Nocturnal will get a say on the matter canonically.
More thank likely TLD will be denied Sovngarde by Hermaeus Mora who will probably kidnap them while they're alive like he did Miraak. We'll then hear in a future game (possibly TES6) some uncorroborated legend about the Warriors of Sovngarde stopping at Apocrypha to free TLD before raiding Hircine's Hunting Grounds.
TLD being trapped in Mora’s realm makes the most sense when it comes to where TLD will end up during or before the events of TESVI. The Hero of Kvatch’s story ended with them mantling Sheo, it’s most likely TLD’s story will end with them trapped in Apocrypha.