I may be reading into formality a bit too much with this, but historically releases the releases have been announced on behalf of the technical steering committee. The wording could simply have been based off the fact that the previous 2 release managers were TSC members, but it does seem appropriate for the TSC to make the announcements.
I'm working on updating the release documentation right now and we have the same scenario of a committer as release manager in 0.3.1 so it seems like a good time to iron out this detail.
