Is the TH-9 an evolution of one of their earlier designs?

I had never seen anything about the TH9 till you posted this thread.  A little search turned up this article about the Taurus 809.  I found another review which stated the TH9 is a refresh of the Taurus 809.   One article mentioned the 809 was a hammer fired version of the striker fired Taurus 24/7.  Taurus is continually changing their product line and it is difficult for me to keep up with all their product changes.   I think this is a reason Taurus has extended service times is because of the number of different firearms they’ve offered over the years.   Taurus discontinued the model 94 22 LR revolvers and no longer supports them.   Unfortunately they’ve discontinued so many models owners are left with no source for parts.

https://www.thetruthaboutguns.com/gun-review-taurus-model-809-9mm/

The TH-9 is essentially an updated PT809.

I had one for about two years. Not a terrible pistol, decent sights, fully ambi.

However the trigger is gritty and heavy, the finish is pretty thin, and the mags even though they are Mec Gar rattle when full

Still though for a sub-$325 pistol it's not a bad pistol at all