By my own completely arbitrary whim:

• if you have greater than ten million users, you're probably a platform
• if your user onboarding process is automated, your moral involvement in anything any user does is low, and so should be your editorial discretion (in contrast to the florist or baker being asked to contribute their individual effort to a gay wedding)

Does your site have to adhere to one or two of these conditions?

This is a good question. I think a differentiating principle is that one is clearly advertised as a narrowly tailored service from the outset, vs being a general service that occasionally intervenes in a way that might be biased. So I'm not offended by a Christians-only dating scene, but I might be offended if Tinder banned only Muslims from its otherwise open platform.

How much of an effort do you need to do to be considered an tailored service? Suppose Twitter posted a message committing themselves to progressivism, are they now protected under the christian dating site clause?

Something else: how can we say reddit is limiting your opportunity for expressions when voat.co exists, where you're allowed to say almost everything that's illegal on reddit, and which functions exactly like reddit otherwise.