UDR has been deprecated in favor of pglogical, which is based on better code already available on PostgreSQL (and production ready... actually we are using it with customers on production systems).

There will not be any BDR release for 9.5. That has been commented may many times on the pgsql-general list.

There will most likely be a 9.6 version, but it won't run on stock postgres (you'll still need to have a patched version of postgres).

If the rest of the features BDR relies on get in for the PG 10 release, then there will be only a BDR extension which you'd have to install (no patching postgres)