If the social interaction is regulated and forced, then it is not genuine.
Of course it's not genuine or sincere if it's forced, but who ever said sincerity was required for social interaction? Come to think of it, who said that it would be forced interaction? The invitations can always be easily given at a more appropriate time: after school.
Have you ever studied a foreign language in class?
I took five years of Spanish between high school and college. In high school it wasn't quite as in-depth, but in college, they only let you speak Spanish once you're into conversational Spanish classes.
I always hated when we were given role-plays to do. Or, "Habla de las ropas en la tienda" (Talk about the clothes in the store"). What the fuck do I care about clothes in a store? Do you know what my shopping consists of? I go in, find the pair of shorts or a T-shirt that I like, make sure I find one that will fit, pay, and leave. It takes me about 3 minutes per item. I don't need to talk to anyone about it in English *or* in Spanish.
That's a "forced" social interaction. In my mind it never helped me learn Spanish any better because I didn't know what I was supposed to say in English, let alone in Spanish. "Esta camiseta es azĂșl." Whoopdie fucking doo, the shirt is blue.
Once I got into conversational Spanish classes, *that* was what really helped me. Being able to talk about what I was going to be doing over the weekend, how my classes were going, things that actually were relevant to my life, I became pretty close to fluent in under a year. Now, two years later, I could still carry on a conversation, albeit slowly. I'm convinced I could achieve fluency in about a month of total immersion. I can't say the same for the year before conversational Spanish.
The point being, when we force social interactions, we're not equipping children to deal with the real world.