I will stand by that Zenos was meant to be dead in 4.0 and he has been rewritten back into the story haphazardly to make him work.

Zenos had no idea he would even body hop after slitting his throat with his katana, do also bear in mind this body hop happened after his body was moved and transported to his unmarked grave where Elidibus snatched the body, all before Zenos woke up inside the resistance Elezen, that is a pretty damn weak pull of the lifestream with someone who willingly wanted to die.

Elidibus showed his face(as Zenos) to Varis in the very clearly body stature of a typical Hyur male, Zenos body stature is far far larger, we knew by this point 2 Garleans having big hulking frames (Zenos and Varis) and it wouldn't have been unreasonable to have such a frame be present and have us think it is another Garlean(like the emperor Solus) and then do a gotcha and go it is Zenos's body.

Elezen Zenos 1st speaking scene could be completely cut and nothing would be lost and we wouldn't have a minor plot hole of a Resistance member dead in Castrum Abania and Elezen Zenos flying off on a Garlean Warmecha that is never spotted, talked about or seen ever again, it literally goes poof from the story.

Elezen Zenos 2nd speaking scene does exactly what the 1st one does but puts him in a more believable area hence why the 1st scene can be completely cut, this scene is here to establish Zenos is still alive somehow and he wants his body back to continue the hunt with the WoL.

Zenos's dreams are not mentioned at all until patch 5.2, straight up an addition that could've been handled way better if they really intended to use him, why do I think this, Black Rose, Black Rose was just a sidequest in the Fringes until the MSQ picked it up, this made Black Rose feel a lot more intentionally added. Aulus would've known about the dreams Zenos was plague with, the man was one of Zenos's closest associates and Aulus having such an affinity with anything related to the soul would 100% be interested in Zenos's never ending dreams, they easily, easily could've been in a bit of notes in the Ala Mhigan Resotorium that an NPC could've said passing mention at some point prior to 5.2 that Zenos was plagued with a dream about an unknown place, vague enough stuff that could've pointed to as foreshadowing.

Zenos was meant to die, the story had changed at some point between the writing of 4.0 and the 4.X patches, this then affected the 5.X story and patches as Zenos had to be explained, they explored everything they initially wanted to with him in 4.0 then they had to add beyond that to give him a narrative purpose and he has suffered for it because they had to take away Zenos's best part his entertainment value.