I swear H and K talked about that in a recent podcast. I’m trying to recall which one, but they said something like:
We don’t know where Thomas went in FTL but he and Ella were kept apart until Rumple got what he wanted in SB, which was the deal with Emma (which was of course to find his child, which was similar to his deal with Ella). So until Rumple got what he wanted Ella and Thomas were separated.
So Thomas broke a deal with Rumple but is alive to tell about it then huh ❓