There will be some. Probably somewhere around .5 volumes, due to atmospheric pressure it will not lose all dissolved CO2.
You can add some fresh S04 if you'd like. I think I did, but don't remember. Also I bottled using DME but weighed it like was corn sugar. The brett will probably consume damn near all the DME. I poured one of these about two weeks ago and the carbonation was about right if you asked me. I targeted about 2 volumes and left wiggle room for it to go a little bit higher.