do we have any evidence of any more Type 054B FFG being built ? only 2 units launched so far
There is definitely more type 054B will be built, but why the pause? The pause is more likely decided even before the first type 054B was built.
They didn't say what was the reason but we can guess with past observations like
1. Why only 2 type 054 were built?
2. Ditto for type 051B, type 051C, type 052 and type 052B.
3. Also why built only 2 type 052C, then paused for several years before building subsequent ships?
Maybe, just may be like type 054's case, they have to wait for certain technology development to bear fruit before building the improved variant but decided to proceed just like the case of type 054, to gain experience on building the new hull and to test performance of the hull design and propulsion etc in post-comissioned sailings.
If above is true, the iteration of type 054B series may have a few surprises in propulsion, electronics and weapons.