You're right, I dont know that they are a psyop. I do, however, know that the position of 'voting is not worthwhile if you are a leftist' that they are taking above is the same position that many psyops would like to have in the minds of leftists. Put more simply, what might they have said differently if they were a psyop? Nothing, I presume.
It is better to root out psyop talking points that diminish our ability to form a collective voice, than it is to allow foolish notions like 'dont vote' to continue in our spaces.