Sometimes, but they come from different environments with different water chemistry, so technically no.
Platies come from water with a GH around 200ppm and a pH above 7.0.
Siamese fighting fish come from water with a GH below 150ppm and a pH below 7.0.
Some male Betta splendens (Siamese fighting fish) are quite peaceful and get along well with other fish, but others can be real nasty and go nuts and attack any fish they see.
If you want to try keeping them together, you need to get the GH around 175ppm and keep the pH close to 7.0, and monitor them closely. If the male Betta shows any aggression towards the platies, you have to separate them.
I keep hearing this term sorority and I have just surmised that it means a whole mess of females housed together. That's a scary thought. Question: If a man speaks and there's no woman to hear him is he still wrong ?
I kept my betta with 5 harlequin rasboras for 3 months and all the betta did all day was hide in the plants. I got him his own 5 gallon tank and he now is out and about most of the day. Male bettas prefer solitude in my opinion.
Also bettas especially don't like other fish with colorful fins. I answered NO in the poll.
Yes, a betta sorority is a tank of female bettas. Things can go wrong - some females are as bad as males for aggressiveness, there must be a minimum of 4 females, the tank must have a lot of decor etc, so they are not as easy as other fish.
Honestly it depends on the betta. I have kept females in a well planted tank with platies and they were always fine. A male? Thats different. I suppose if you had a large tank with lots of plants you could buy a baby betta and raise him in the tank that way he'd grow up used to other fish. Or even buy a young betta. Thats the way I think it would work