Move some deprecations along.

It's not postponed. The first "removal" is from the docs. The second is from the code. It's supposed to be deprecated and documented for about a year and then deprecated and undocumented for about 6 months, and I don't know when the next release will be exactly, so I picked a date that's probably around 6 months from the next release (maybe a bit more, maybe a bit less). It really should have been undocumented with the last release, but clearly it got missed.