MIL uninvited herself from our wedding

I don’t know what to make of this, but I believe my MIL just cut us off before we could go NC? I think? I don’t really know what‘s going on.

My MIL was bitching about my fiancés grandma, how she‘s a terrible MIL and especially how she treats fiancé‘s cousin‘s GF who just had a baby after a miscarriage. I didn’t get into it, as I found it inapropriate to bitch about somebody I barely know in front of my fiancé and his dad.

She then turned to me and said if there ever was something I had a problem with to just speak to her… and I guess I swallowed that bait hook, line and sinker. We‘re childfree and she knows, but it doesn’t stop her from bringing up us having children every time we meet her.

I told her that I don’t really appreciate those comments and would really like for her to stop it.

She immediately threw a tantrum how with our generation you‘re not allowed to say anything anymore and she never even said anything to begin with. She ended it by saying she won‘t attend our wedding.

They day after my fiancé got a message from his dad telling him we don’t know what we‘ve done, how they have a lot to think about now and that they are not on speaking terms with „the bride and groom“. He‘s sure she wrote that from his phone.

This was last week and we haven’t heard anything since.

Edit: She‘s not my fiancé‘s mother. She‘s his father‘s second wife. His parents have been divorced a long time.