The last minor release of Apache NiFi 0.x line was 0.7 . As per
 it is no longer supported. While members of the community are
free to make incremental releases there as they need it is no longer
subject to definite backporting of critical fixes or security
I plan to do the following:
1) Remove 0.x downloads from the downloads page.
2) Update on our wiki page wherever we have references to 0.x to be 1.x based.
3) Update our security page  to highlight that 0.x is no longer
supported and will not receive vulnerability back ports or critical
4) Update our release notes page  to highlight on all 0.x releases
that they are no longer supported.
5) Send an announce email to the users list advising that the 0.x line
is no longer supported.