“Then, a few days ago, I listened to a shiur about how to counteract all of the suffering, it is our jobs as Jews to spread even more happiness during these days to bring on the Geula”
Let me guess, Chabad?
The halachah is clear that we decrease simchah. And no, the inverse is not “the Chassidishe shittah.” It might be that of ONE Chassidus, but not the rest. One thing to consider: if a group/person willingly broadcasts on the internet and elsewhere that “the geula is here!” that group will inherently treat the 9 days less seriously/as a formality, so take it with a grain of salt.