User blog comment:Real Godisme/Chapter 481/@comment-26826245-20160411170518/@comment-7418318-20160411174710

Siegrain suspected that she would have become wizard saint level in those seven years between her death and his conversation with Ultear, if she hadn't died.

To me that doesn't sound like she already was wizard saint level at her death though.

Not to mention that we have no idea how strong the 10th wizard saint is (or who he or she is). It's (at least theoretically) possible that both Lyon and Gray are already strong enough to become members of the wizard saints, but weren't chosen for political considerations (just like Laxus and Gildarts).