As reported on PWInsider, it turns out that Taz actually owns the rights to the FTW Championship and never signed over any of the rights to Paul Heyman or ECW, meaning that he can do whatever he wants with the intellectual property and belt design.

“Taz actually holds the copyright on the actual design of the belt, which allows him to do whatever he wishes with the design and the FTW intellectual property within professional wrestling.

If he ever wanted to merchandise the belt, such a replicas, t-shirts, etc. Taz would be well within his rights to do so.”

It's worth noting that Brian Cage is scheduled to defend the FTW Championship on AEW Dark this week, so it seems that AEW is actually going to recognize the belt as one of it's championships.