No, I dont think you quite get it.
If the album does not exist it has to be added to Musicbrainz using the Submit New Release option or directly via the Musicbrainz Website.
Once this has been done, make a note of the releaseid that has been allocated to this new release.
You can then update your songs to this release by using Match Songs to Specified Release and entering the releaseid of the newly created Musicbrainz release that yo noted earlier. (The release will not be found by the searches until the indexes are next built, and this happens every four hours that is why you shoulds note now the release id after the release is created)
Now if you have a Puid for each song (via Retrieve Acoustic Id) you should have a puid and a recording id for each song and the Submit MusicBrainz/Puid Pair will sending this pairing to Musicbrainz.
But as we are moving to a new fingerprinting system it would be more useful to replace the last step with Submit MusicBrainz/Acoust Id Pair