Comment # 4 on bug 998663 from Takashi Iwai

One significant problem in the scenario to switch from 64k to 4k after the
release is that it shall break kABI.  It means the KMPs that have been built
with 42.2 GA kernel wouldn't work any longer after switching to 4k.  So, if we
want to keep KMP compatibility, the switch after the release won't work well,
unfortunately.

Of course, we may enforce all KMPs to be rebuilt after the switch happens.  But
we have no control over 3rd party stuff, so we can't guarantee it.