This has a ton of merit too, as Prince Valanar canonically disguised himself for a very long while.
As per this link: https://wow.gamepedia.com/Prince_Valanar
" All this time he was disguised as Counselor Talbot, ready to lead the Alliance forces in the hands of the Lich King. He was stopped by Thassarian."
Which is fascinating! We saw the end result of this during the questline in Borean Tundra, where we kill him for the first time.
Fun Fact: Valanar, as I said, is still not anywhere around to be rezzed by the ‘dark forces’. He could very well be a missing blood prince now. Or it could mean nothing. But I hope it leads to something.
As for Lightforged Undead, I genuinely hate the concept quite a bit. I will never put down someone for liking it, but me, personally, I just cannot stand it and do not support it. Quite like Venthyr. I think if either of those were added with no sign of San’layn, I’d be done. I feel like I sound kind of petty, but I’d never start an anti-thread on either or even bother going on either pro-thread to say “I don’t think these should be added” even though I genuinely dislike both. (These days. I used to express my disdain toward the ideas. Nowadays I stick to this thread. Though, as every forum goer is allowed to do and do so in THIS thread, I’m also allowed to express distaste for an idea.)
With Venthyr, it’s the post I wrote above. With Lightforged undead, I wrote a long post as to why I do not like them on one of my alts (comically, in that thread, someone called me a human paladin which I corrected by swapping to Falls). Same thing on Hordeside, it simply is a terrible concept (to me, again this is my personal opinion).
I just had to look up on search: Fallynn “Lightforged undead” and it’s not hard to see my opinion on it. Lately I’ve kept my mouth shut and just rolled my eyes, because it’s not worth arguing. But yes, I think I’ve made my thoughts on this clear.
Edit: Also, I wanted to share this piece by my guildie for another one of my guildies 
Credit to: https://twitter.com/LycaonElysion/status/1324445069408165888