In Before The Storm, Genn mostly forgave the Forsaken people after understanding that they are normal people stuck in a horrible situation, and that his grievance is specifically with Sylvanas (especially after realising that she sees the forsaken as a tool rather than her people).

Tyrande is now literally the incarnation of Elune's divine wrath, and in 8.3 she spells out exactly what she is going to do: she won't sign the treaty until she gets to sign it with Sylvanas's blood, then she's off to figure out why Elune has seemingly abandoned her people.

We know that Tyrande is going to play a part in Ardenweald's storyline. As for Genn, if he shows up, he's probably going to be going after Sylvanas (IMO it would also be a great chance to have him meet his son again)