System-upgrade across two releases raises an interesting End-of-Life
policy issue. If system-upgrade from N-2 to N is so important it will
block release of N until it works, how do we explain why it is no
longer important after four weeks when N-2 reaches End of Life?
Four weeks is little time to allow users who chose not to upgrade to N-1
to move from N-2 to N. Do we say "After four weeks, the only supported
mechanismm is new installation of N"? That is clear and simple,
consistent with the EOL schedule, but denies system-upgrade is such a
critical facility.
Should system-upgrade be formally supported for three releases (18
months?) That would tell users they may count on it for their upgrade
plan, but it is a significant change that could involve FESCo.