Friends Miscommunication

So my friends who graduated my uni are coming back to visit for hoco. I was super excited the three of them asked to stay with me, as they are part of this larger graduated friend group and I thought that them staying with me would mean I would get to hang out with the whole group. It's been hard to get them to give me details about scheduling, which I get because they work, but I lowk need to know for my own schedule...I was under the assumption that if they didn't give me any other info, we would just be chilling together. There's this event that happens every year where people will pregame(party before) for in their friend groups and then go over together. I thought that my friends would pregame with me at my party since they're already staying with me. Just found out today (4 days before said event) from one of the other members of the friend group who isn't graduated, that she is hosting a pregame and the friends that were staying with me were planning to go to that. This was me eavesdropping, so I asked her about it and she kind of obligatory invited me to come, but that my 4 other friends (not in the group but who were going to my pregame) were not invited because of too many people. ok...a bit shady. I texted the friends who are coming to stay with me to confirm if this was all true, but they haven't responded. I honestly feel a bit disrespected, because I'm letting them stay with me, but wasn't communicated with about these other plans that I wasn't even initially invited to. If they wanted to party with her, then they should have stayed with her? I don't know if any of this makes sense, but I feel kind of insane and I don't want to be pissed off the entire time they're here.

Oh and get this: my roommate is (or maybe was at this point) best friends with the other girl hosting, but she also wasn't invited! I'm at least not the only one confused and upset.