I think it's worth noting that in 2011 Pittsburgh, Syracuse, Missouri, Texas A&M, TCU and West Virginia all were officially introduced as members of their new conferences within a 3 month time period. That entire time, the Big Ten didn't make a move. It wasn't until the next fall, an entire year later, that the Big Ten made a move and added 2 teams, which was incredibly obvious as being solely for financial gain.
The Big Ten is not going to feel rushed to expand. The ACC GOR is in effect until June of 2036. The Pac-12 GOR expires in June of 2024 and the Big 12 GOR expires in June of 2025.
The Big Ten's media contract expires in 2023 and when they renegotiate, if they think they might expand, they are going to want to know which 2 teams are going to be in the conference when they go into negotiations for how much their product is worth to various media companies. Additionally, the media companies are going to want to know who will be members of the Big Ten before they negotiate as well. Otherwise, you can only make a bid based on who is a member of the conference at the time.
If the Big Ten thinks they need to expand or decide they want to for financial reasons, they will likely wait until next year. It gives time to let the dust settle a little bit, it provides time for the Big Ten and it's presidents/ADs to really figure out what's going on, it allows them to analyze their options should they choose to act. But it also would be before members of the Pac-12 and members of the Big 12 renew any media contracts they are currently in with their respective conferences. I would be absolutely shocked if The Big announced anyone as being a new member to their conference within the next few months, especially if that's Iowa State. We are not their #1 choice, strictly from a financial viewpoint. They are going to weigh their options first.