User blog comment:GreenHornet/6 Months Since..../@comment-1647442-20151203193506/@comment-3163813-20151218013922

I don't think it was ever confirmed that Disney wanted another season. It was confirmed, however, (at Comic-Con 2015, no less!) that a script for a 'Phineas and Ferb' theatrical film has been completed and is awaiting further development at Disney. It's not on the release roster yet, but it will be, hopefully before the decade is out.