Yes and no.
Blood Elves did what was best for their people solely post Arthas.
High Elves are the ones who stuck it out with their comrades as a lot of them fought with humans. Or had friends and what not. Like Dalaran Elves are most alliance leaning.
There is a lot more nuance to the Blood Elves doing thier own thing. But I’m just giving a quick and dirty version.
and the Silver Covenant. Which is the main faction of High Elves that exist.
To be far, most of the human kingdoms didn’t see the Orcs as a threat until Stormwind fell to them.
This includes the whole kingdom, including most modern high elves. The only ones who wanted to be part of the Alliance were those who followed Alleria beyond the dark portal. The elves of Dalaran are a mixed bag, a lot of those who were Dalaran citizens at the time are now blood elves.
Also it also includes 100% of worgen.
Actually this was addressed during the retaking of Lordaeron. She met the Margrave and she was told that Calia Menethil is indeed undead whether raised by Light magic or Shadow magics or Shadowlands magic. She’s undead and her condition is no different than a Forsaken. Where we may see a difference, there is none, and when the Margrave tells you that. Believe it. Shadowlands basically confirmed she’s no different in terms of what she is.
Look forward to Lordaeron being rightfully returned into the ranks of the Human Kingdoms through the venerable Queen Calia of House Menethil, with all of its inhabitants, undead or otherwise.
Come back home.
Next we need Stormgarde rebuilt ingame.
I forgot about that, but then again, I suppress any and all memories of SL.
Lordaeron died. The population was literally stripped out of their lives and humanity, turned into undead.
Do you really think the Forsaken would care if the king stripped her of her title after Arthas and the Scourge? Sounds a lot like burocracy nonsense. Besides, if such things mattered to Forsaken, they’d have never followed Sylvanas.
It’s more complicated than that. 20 years happeend between WC2 and WC3. The individual elves’ intrest changed. A lot of people who wanted to be part of the alliance in WC2 are now blood elves, and a lot of people who didn’t, are now high elves. For instance we know a significant proportion of Sunreaver blood elves are born and raised in Dalaran, cause there’s an NPC that tells us that, that she had lived in Dalaran for centuries before being a blood elf.
Not all of Lordaeron died.
Scarlet Crusade is all that is left living of that once proud nation
That I would love to see, as according to the story line the Alliance won the battle there and the castle was largely repaired during that warzone. So the Alliance should expand and secure the area. But we will never retake Lordaeron, if anything maybe it should start to have some living inhabitants. To reflect the still living Lordaeron citizens returning to their homes. At least in this situation I doubt Anduin would be threatened by that act and decide to kill them all to make a point 
Yes, and all factions take great pleasure in their extermination 
I mentioned Human Kingdoms, not Alliance. Lordaeron can stay Horde-affiliated. I just want it to have a good relationship with Stormwind. Hopefully living humans will populate Lordaeron as you said as well.
There are survivors living within the Alliance. That was made clear in the Before the Storm novel. Matter of fact Anduin got the idea for the meeting between the living and raised family members to take place for a servant of his family who was a survivor of Lordearon who wasn’t sure what happened to the rest of his family.
Also not all of the Scarlet Crusade are from Lordaeron, a lot come from elsewhere, they have recruiters in other human nations.
Once again Blizzard could have written a story and a questline showing how and why Calia should be queen or not, but at the end of the day they want to get to the finished end without putting in the work.
I do like the character for the most part, but I understand why people see her as being forced unto players who don’t want or need her.
So wait, if Arthas was the last king of lordaeron does that mean us killing him was technically a peasant revolt?
No, were are “champions” damn it!
True, Arthas and the Scourge / Forsaken made victims all over Azeroth
Yea, there’s that. The narrative was fine, but I still think there should be some plot out there for Scarlets within the Alliance. One that does not portray them as the villains.
This SUCKS. Someone better get on changing the quest dialogue because I’ve about had it with Danuser’s fixation with ruining warcraft lore for the sake of installing “strong female champion” in places of power when they haven’t earned nor deserved such treatment.
Calia Menethil sucks as a character. Completely. The point in being forsaken was that you originally were a leftover of Arthas’s scourge in Lordaeron that broke free of his control. Where was the monarchy then? Abandoned the people of Lordaeron - you find in Legion that Calia had been hiding from her people the entire time! Barring that, being forsaken meant that others of your still living family have disowned you, you reek of death and are rotting, the living would sooner cull you than speak with you.
Calia has gone none of those things. Only person in Lordaeron to become arguably more physically attractive after dying, expects now to be referred to as a Queen if the quest dialogue is canon (even though she abandoned her people), and regularly councils with other living members of the alliance. Stop gutting the Lore, it was bad enough when literal demons joined the alliance!
Metzen freakin save this game man