It will be a unanimous vote. That's how these decisions are made. The SEC doesn't go this far into the process without everyone being onboard. Texas A&M has come out in support of the additions, albeit begrudgingly, I'm sure. So if the Aggies are OK with the moves, Mizzou will certainly be OK with the move. We're talking about approximately $20 million more per school per year with these additions. Mizzou's annual revenue will still be in the lower tier of the SEC, but turning down that kind of cash would be institutional malpractice, regardless of the impact on the field or the recruiting trail.
Yes, adding two quality football programs makes it harder for programs like Mizzou or Mississippi State or Arkansas or South Carolina to win the SEC - but it's extremely hard for those programs to win the SEC anyway. We don't know how the divisions, pods or schedules will look just yet, but if Mizzou trades annual games against Florida and Georgia for annual games against Oklahoma and Texas, how is that much harder?
As for recruiting, I think adding these two programs is a net gain for Mizzou. Texas and OU can still only sign 25 players per year, but their additions should make the SEC more appealing to more prospects in Texas - and they can't all go to Texas and OU. There's an endless supply of players in the state.