Friend has invited whole friendship group - minus me

Context is that we were a close uni group who lived together in a dorm and then all flatted in close proximity for 3-5 years from 2015-2020.

Said girl was my first friend at uni and we dormed next to each other. We became really close and spent so so much time together and remained that close until she met her partner in about 2018 and then a more third wheel friendship until I left uni in 2020.

Our friendship group was inseparable. There was maybe 7 of us as constants and 12-13 by the end when we left. Most of the group were coupled up - I wasn’t.

Anyway I moved back to my home city and she moved overseas with her partner. We have stayed in touch since but not actually seen each other since 2020 because of that. We talk every couple of months etc. I still see the rest of the group occasionally who are in the country and come into my city / or when I am in theirs.

I caught up with one of the guys recently and he said he would see me at the wedding and I didn’t think much of it. Just assumed the invites were either coming / being sent.

Anyway just seen on socials she got married on the weekend and the whole group was there. I realise they must have known or discussed I wasn’t going as no one messaged about my travel plans or accomodation etc closer to the time. Some of these friends have travelled internationally.

I’m so baffled and just feel like I could never do that to a person. It feels so morally wrong to just not invite one person and I also don’t understand. Nothing happened between us, we literally last spoke like one month ago about normal stuff? So odd. But now I have this desire to cut the whole group off. It feels like a whole sham of a friendship circle.