And PT wood can be wet on two fronts. It can be wet from the treatment and from the fact the wood itself went directly into the treatment tank process without any natural or kiln drawing time.Often, when you get PT lumber, it is litterally dripping wet, sometimes it is nice and dry to the touch. Rule of thumb is to let it air dry about 6 mo.
But i would never paint PT wood, it expands/contracts too much to hold paint. Solid stains would work much better.