Relicensing OpenSSL

Of course I can put a work under multiple licences. I can enumerate these (say dual-licence MIT and CC-BY)
or use a criterium (say, anything the OSI has ever approved), and this certainly
does include not-yet-released future versions of existing licences.

Now, whether I *want* the FSF to be able to put out licence terms I wish to use
for my work without further review is the other question, but that’s independent
of the legislation I work under.

It’s not the FSF that does the actual licence grant, it’s just me.
I could let the FSF dictate the terms (by using GPL-vˣ+) or not.

There’s something in German law that prevents me from completely giving up my rights,
and something about being able to reclaim licences after thirty (IIRC) years,
but that only applies to exclusive licences, which OSS licences aren’t
(meaning I can still decide later to put another set of terms onto some work,
which is precisely not possible if it’s in the public domain).