Im looking for the roadmap of the feature - master-mater replication.
In Postgresql-10, Bi-Directional replication (BDR3) has been embedded in it.
It's available as an extension, it's not part of PostgreSQL 10.
PostgreSQL 10 has single-master publish/subscribe.
Are there any plans to have built-in master-master replications in future versions of Postgresql 13 (or) 14 ?
My understanding is that in the long term that's probably the case, but I don't speak for 2ndQ or anyone else when saying so.
It's exceedingly unlikely that nontrivial multimaster logical replication would be possible in PostgreSQL 13 or even 14 given the logical replication facilities that are currently in the tree. A lot of things would need to be done, and in many cases the approaches used in the current external MM replication solutions could not be directly adopted without a lot of redesign and revision as we already saw with the addition of basic logical replication functionality in PostgreSQL 10.
Personally I'd be delighted to see people working towards this, but right now I think most contributors are focused elsewhere.