I'm messaging someone I had previously matched with on tinder out of the blue on facebook
What is the reason why you are choosing to message them?
I think I might want to add them on facebook instead of going out with them
There is no point in messaging them at all if you do not want to go out with them. Since it's tinder, if you are not interested in seeing them in person it is probably better you just don't send them a message at all.
I'm probably going to message other women on tinder.
If you want to be friends with someone you initially met on tinder, that's okay. You should just make sure you're honest about what kind of relationship you are looking for with that person so they don't feel misled.