Pinkie's role in this episode was really relatable tbh.
A lot of people are saying that it's on Pinkie for not expressing herself correctly but i think people should realize that not everyone is as good as expressing themselves in serious situations and it's not an ability to take for granted, specially if it involves kids or some type of condition that affected the way one expresses themselves, even so, I personally found reasons to listen to Pinkie, not because of the bias caused by her being relatable but because she's the only one who recognized the parasprites, the mistake of the whole gang concerning Pinkie was that they discarded her strange involvement for being the way she is, and not giving her the benefit of the doubt, stopping for a second and ask "why are you doing this pinkie?".
Pinkie not expressing herself correctly is actually benefitial to the episode contrary to popular belief, because the point it's trying to convey is that you shouldn't invalidate other people's competence because they don't appear to be smarter than you, and that if you take your time to consider what they're doing, you might find that they could be worthy of being listened to.
heck, if they had considered Pinkie for a minute, they would've noticed that only she knew about the creatures, the rest of this scenario is self-explanatory.
So yeah, what the episode is trying to say is that... there are gonna be people you're gonna underestimate, and they might not always help their situation because of the way they express themselves, but they are not to blamed about it, the best thing you can do is to give them their time and consider what they say, just like with any other person, because their ability of expressing themselves doesn't equal their level in intelligence or education.