Side note: for somebody with a "gnu.org" address, you're showing
some really bad taste. Do you know that the FSF ends up asking for
a hell of a lot of paperwork and other crazy things to take peoples
submissions. And they actually want the copyrights signed over, so
that they can change it to _any_ license.
The DCO, in contrast, is a paragon of simplicity and clarity, and
doesn't ask you to sign away any rights.
You are misinformed. The copyright assignments from the FSF explictly
state that the code will always be free software, and they grant back
all rights to the code you assigned to them.