Q: Our local pastor told me that some liturgist told him that the double alleluia at the dismissal is optional during the entire Easter Season. I’ve never heard of this. Is he right?
A: That liturgist is wrong. The double alleluia is added during the entire Octave of Easter and again at Pentecost and its Vigil. That’s it.
See the Missal, #69 at the end of the Easter Vigil, #13 at the end of the Pentecost Vigil, and the end of the texts for the Pentecost mass.
I don’t think anyone will be spending extra time in purgatory for singing too many alleluias on earth, but rules are rules.