Yep because it's gentiles who gather in synagogues who reject Jesus Christ.

Actually yes! That's precisely what Ignatius describes. Jesus wasn't referring to all synagogues, but a new practice in two cities. Ignatius makes clear they were uncircumcised Judaizers, and reading between the lines of Ignatius implies they asked the local Jews if they'd have permission to be called a "synagogue", and so they ended up being called "Jews" too by these liberal birth Jews who broke the tradition of every other Jewish community in the world. If Jesus said something like "all synagogues are of satan" that would be different, but he said this "synagogue" was of satan implying others weren't. Basic logic and basic history.