From PC Patch note V3.0.10
https://forums.elderscrollsonline.com/en/discussion/355480/pc-mac-patch-notes-v3-0-10#latestGeneral
- Permanently summoned pets, such as the Unstable Familiar or Feral Guardian, will now heal back to full health after exiting combat.
I can only gather that the First Incremental patch for Xbox One & PS4 users will include this, which means that pet health regeneration is not completely dead.
(Like a partial necrotic resurrection from when it first got terminated back in the initial release of morrowind on the PTS, PC & consoles)
But either way, ZOS did something right once again.
If you see me anywhere. Know that I am sitting back with a bag of popcorn, watching as ESO burns the goodwill of its player base with practices that only disrespects the players time like it did to me and many others...
If a game does not respect your time, best thing to do is move on from it and find something else.