SPEED FORCE NORA ISN'T THE REAL SPEED FORCE AVATAR.
Since Nora's sudden appearance, she's been acting a lot like someone who we knew as Hunter Zolomon, and not the mother of Speed itself. If anything, Speed Force Nora is the Avatar of the Negative Speed Force, which could end up creating Red Death (YES I STILL BELIEVE RED DEATH WILL COME) at the end of Season 7.
Eobard Thawne tried to posses the body of Nash but that obviously failed. With Nash being the only Wells alive and being the bridge to Eobard Thawne, I believe that when the Speed Force was revived, it wasn't the same speed force we know and love. Part of Thawne was born in the new Speed Force, some how. So...idk...does this mean Nora and Thawne are merged? I have no idea. I guess her appearance can explain why we haven't seen a Wells in so long.
Sure they're goal is stop the new Forces, but what will they do after the Forces are stopped? That's where Thawne appears out of nowhere and tries to take the power of the Forces for himself. Or maybe, with Nora being able to give barry speed, that'll open a bridge for the Speed Force to posses Barry Allen (like how Reverse Flash possesed Barry Allen in the comics after Paradox was defeated).
So when could we possibly see Thawne? Probably sometime during season 8. We are seeing JPK returning to play Nora West as well as Jordan Fisher as Bart Allen, so we could see the Tornado Twins ending up evil at the end cuz of Thawne.