Aggy started flirting with the SEC in 1991, if not earlier, when it was becoming clear the SWC wasn't going to last. To be fair, UT was flirting with the SEC, Pac 10, and Big 10 at the same time. Arky obviously made the first move, and Frank Broyles made it clear he wanted UT and A&M to eventually join Arky in the SEC. Any talk of Arky leaving to get away from UT is pure revisionist history.
When the SWC imploded, UT's hope was to join the Pac and A&M wanted to join the SEC. Both wanted to stay together so the compromise was a marriage of convenience with the Big 8. That marriage has worked out about how you'd expect since many of the members had their eye on another partner from the beginning (CU/Pac, A&M/SEC, Mizzou/Big 10 (even though they had to settle for the SEC), UT flirting with the Pac).
Not trying to derail the discussion into conference realignment. Just pointing out that none of this is new, none of it should have been a surprise, and nobody "suddenly cut bait" as described above.