He’s obviously not, which is stated there, but reading skills are too ‘OP’ nowadays.
True. There is one connection, though: DH is represented by the colour green, and Argus is the ‘Emerald Star’ here. 
But there’s one more thing: Argus as the planet has more or less been the main objective of DHs. Oh, and the Fel theme, of course.
The point is, both classes can’t have him.
Ditto (in the post linked above).
Well, technically speaking, even the Eternal ones are just bots, as far as I recall…
As for V-07-TR-0N, it might be a cool reference to Mimiron’s Head from GvG.
Good point, by the way.
Lemme return to this point.
As far as I understand, all Titans were originally from the domain of Order, rather than Death. Sure, there was the Sargeras incident, but as for Argus — I’m not all that well versed in lore, wasn’t it part of Zovaal’s shenanigans anyway? In that case, they might as well have chosen someone from the realms of Death, i.e. an Eternal One…
I do understand why Primus, though, since this whole Maldraxxus thing looks like yet another rendition of the whole Scourge thing, almost a reuse, so this one is fitting thematically.
PS Come to think of it, Argus doesn’t even belong in the Shadowlands (his soul hitting the Arbiter and so on is the Jailer’s scheme — Argus is no mortal, after all, and has no place in that mechanism), and as for ruling Undead — that’s what they do in Maldraxxus.
UPD Here’s the lore, and it explains it all, more or less:
https://wowpedia.fandom.com/wiki/Argus_(titan).
PPS Amitus almost looks like Cariel Roame ascended. Not that I don’t like Cariel, but dunno if such a decision resembles a cheap ‘expy’…
https://tvtropes.org/pmwiki/pmwiki.php/Main/Expy
And the namce choice is stupid, see above.
(Updated a few times)