Sir, it's nearly impossible to get into all of the details on this thread, but it's more than just "speculation".
Please bear in mind, I am technically an alum of both Miami and Florida (LLM-Tax), and I grew up in Orlando. I'm longtime friends with quite a few Gator alums. I currently live in ATL. I've been surrounded by SEC-SEC-SEC nearly my entire life. The SEC is not happening.
I'm not denying that there were conversations in the past. Also, in the past, geography was a much stronger consideration. The Big 10 taking Pacific-coast teams has largely obliterated that "geography" concept forever. The Gators, and possibly every other school in the SEC, will not support THREE teams from one state, and if the SEC had its choice, they would take F$U over Miami. All day, every day.
The Big 10 conversations have been going on for a LONG time. Longer than can probably be publicly admitted. The first clear public sign was AAU membership. But our former President has been conversing with her friends in the Big 10 for quite some time. And the Big 10 actually NEEDS Miami more than the SEC does (or perhaps more than the SEC admits). And as alums, we should also acknowledge that the Big 10 scratches the academic itch that Miami has, far more than the SEC does (regardless of Austin and Hogtown).
Everyone is entitled to their own opinions on preferring the Big 10 over the SEC or vice versa. But those preferences should not be confused by what is most likely to happen. There is NOTHING "predicate" oriented that is transpiring between Miami and the SEC. Nothing. I never rule anything out completely, maybe there is some President/AD/Commissioner turnover at the SEC and the thinking on Miami changes, and/or the competitive lust to out-do the Big 10 takes over. But short of that, we will not be extended a bid to join the SEC.
I know that some of the younger posters don't understand the deeply-held tenets of people like Christian-Nationalist-Socialists and Lost Causers, who firmly believe that they can manifest Judgment Day and/or the South Rising Again. But the SEC is intent on expanding to represent all 13 stars on the Confederate battle flag, and that means flying the SEC flag over North Carolina and Virginia, the last 2 states on their checklist.
Talk to some really old Bull Gators (or any old SEC boosters). They'll tell you. I (briefly) used to work for a Bull Gator tax partner, who was not afraid to drop the N-word. When they think "you're one of them", old SEC moneybag-types will tell you the master plan.