I think the problem with meeting anyone through Tinder or similar apps is that even if it's just to cycle together, there's still the weird implication of something romantic or sexual. Even if one person makes it clear that they're only looking for friends, there's no way to foresee the intent of the person you're going to meet, and plenty of people don't like taking no for an answer. It just seems like a situation that's prone to being sketchy.
I've always had luck finding people to ride with by chatting to other cyclists on bike trails and such, so I've never really considered going online to look for friends. It's also fun to invite non cyclists out on a ride, especially if they end up getting really into it...that's how I got involved in mountain biking