Tongue thrusting can tip your front teeth, but if you are keeping your tongue behind your incisive papilla, Mewing shouldn't cause your incisors to tip. I've speculated in other threads that what some people have described as a phase of duck-like appearance after they begin mewing results from tongue thrusting that corrects itself once there is adequate space on the palate to keep the tongue from making contact with the incisors and the muscle tone of the lips corrects the tipping once unopposed by the tongue.

So I should be fine with time?

It's hard to say. Some of the other people I mentioned say that their teeth aren't actually tipping, but their lips are just pouting out. Still, logically I think if your front teeth are tipping, you should avoid pressing against the back of the incisors with your tongue and eventually the muscle tone of your sealed lips will bring them back to vertical.