Speculation about Il'gynoth's whispers AFTER BFA announce + cinematic.

[Aucald]

Why do I keep seeing that meme that Azeroth is corrupted?

The pre-7.3 scenario outright states that Azeroth is fine and just has some bad dreamies and a slight arrythmia.

Same with the mental gymnastics that the "third death line" refers to Sylvanas, as if she has become a different person when she died.

Likely it has to do with Algalon's assessment of Azeroth in Ulduar - but he's referring to her protective and auxiliary mechanisms and not corruption of her essence.

Analysis complete. There is partial corruption in the planet's life-support systems as well as complete corruption in most of the planet's defense mechanisms.
Begin uplink: Reply Code: 'Omega'. Planetary re-origination requested.

This has been conflated on more than one occasion to complete corruption. We also only have Magni's say-so for her status, so whether or not she's corrupted would depend on whether or not you believe Magni is trustworthy.

[KrakHed]

Same with the mental gymnastics that the "third death line" refers to Sylvanas, as if she has become a different person when she died.

That's not mental gymnastics. That's acknowledging that Il'gynoth's words are somewhat poetic. To say that line refers to Azeroth, you have to insist that "death" doesn't actually mean "death" at all, but merely "potentially life-threatening injury". Of which Azeroth has had four. For it to be Sylvanas, you merely have to view it through the lens of the common figurative belief many people on Azeroth hold about the undead.

If that's mental gymnastics, it's mental gymnastics either way.

[vertigo12]

This only proves that the Titan themselves although they wanted to make things perfect or think of themselves as perfect being, the old gods easily disproves that surmise and they can themselves be corrupted. First is Sargeras and second who is in the borderline Azeroth.

There is a line stating that the creations of/in Azeroth themselves are the imperfection.

[Xanesh]

Well I saw something that looked a hell of a lot like Illy's bash tentacles and eye tentacles in one of the cinematics, might have been C'thun though his were very similar.

I noticed those too. They were definitely the models used in the Il'gynoth encounter. May be placeholder or reused in Zandalar. May link with G'huun? I'm excited by the implications.