But we already had answers to this. Willing to question her to save his wife, willing to work with the man who murdered her. That is not the story of a fanatic. A fanatic would be questioning his wife that had not seen for hundreds of years due to her ties with the wife; not work with her while she is openly using the Void. A fanatic would have continued with his attack on Illidan instead of immediately stopping at the first prompt by Velen and at least detained him after; not stand right next to him and continue with shared plans.
Turalyon would be a great character to forge an initial alliance with Yrel if she comes, try to advocate for the Light and her Crusade but immediately turn on her when she turns on his wife or commits atrocities. If there is a Light vs Void campaign, Turalyon has perfectly set himself up to be a moderate that wants us to all work together against the greater threats.
If anything the problem is that while the Light vs Void seems to be a central struggle for Warcraft, the Horde has been given almost nothing to work with there. They recently got Calia but I doubt Forsaken players will ever embrace her. They completely failed to capitalize on Zabra, making him SHADOW ffs in the priest hall instead of showing how any race can follow the Light. While Natalie Seline is a great character she immediately robs the spotlight from the previous leadership of the Church of the Forgotten Shadow like Aethalyste. We did get Geyarah who will be a central character Horde side against the Light but has no ties to the Void (and if anyone is a fanatic, she is). So when the Light vs Void happens we will once again have an expansion where Alliance characters will be front and center and the Horde will have no one to relate to.