Hmm, let's recap:
0. Samba has, for years, been a pure clusterfuck to compile and build yourself, attempts at getting community help from the mailing list are always deflected with "don't do that, use SerNet's binaries". Distribution packages as well are not supported by the Samba community, it's SerNet or GTFO.
1. SerNet stops distributing precompiled Samba binaries for free. Thus, users are forced to either buy absurdly expensive "samba+" licenses (250€/server/year!) or to stick to distribution packages, which are still at 4.1.
2. Samba, led by SerNet, stops supporting 4.1.
3. Samba announces "Badlock" _several weeks_ in advance and helpfully points out that, since 4.1 reached EOL a week earlier, users will have to upgrade to versions that are only available from source or as paid SerNet binaries.
I'm sure there's absolutely no malicious intent behind this whole ridiculous charade.
This is a large coordinated effort. Expect patches from other non-Samba using vendors shortly.
Coincidentally, Samba 4.4.0 was released on the same day: https://lists.samba.org/archive/samba/2016-March/198501.html