Nothing bad but usually im wary of this "Let me do better than canon" because it commit the same mistake in some part, let see:

With his allies dying around him, in an act of frantic self sacrifice Eldrad steps into the conflux of energy at the heart of the ritual, allowing himself to be consumed by Ynnead..
I dont like this, whil Eldrad sacrifice was nice and all, he is pretty much the no oficial leader of the eldar right now, and killing him would be a waste.

So begins the primacy of the Fire Caste and the T’au Sept assuming a position of first amongst equals.
....WHY? it feel just sort of.....there, the idea of a god of greater good being form and the implication in canon sound more than just a soft military coup.

As they depart the facility, Yvraine emerges from a webway portal and confronts the humans. Guilliman refuses to give her the information she wants because she’s a foul xenos and he never made any deal with her. Valoris states that he has upheld his end of their bargain, and Yvraine’s failure to secure the information during their last meeting is her fault alone. The situation rapidly deteriorates until the two forces come to blows. The Eldar are forced to retreat back into the webway – they will need to discover the location of the next Cronesword by other means.
Gods no.

It dosent really make sense in this case, it feel the old grimdark "alies cant be alies because grimdark dammit" and it make Guillman really look like a bastard by deciding he dont deal with xenos, not matter they bring him back to life, also Guillman istn so unresonable.