A few possibilities there:
(a) They did vote yesterday, and just haven't announced the outcome yet. If the vote failed, I can't imagine why they'd wait. But if the vote passed, I could absolutely see them passing the results to the SEC front office with the directive to "amend the rules and announce when ready." Which means the rule-managing technicians of the SEC front office are feverishly wordsmithing to get the new rule just right today, and will announce when they've got a finished product. That could take a few days, even.
(b) They didn't vote yesterday for whatever reason, but are voting today.
(c) They voted yesterday, and approved it, but got ticked off at Stoops and Kiffin for stealing their thunder so decided to wait a day to announce, just out of spite. This one sounds far-fetched, but bureaucrats can be petty. Remember Nebraska's president caught on a live mic semi-announcing a couple of weeks ago that B10 football is back and "will be announced tonight," then the announcement didn't come until the following day? That was the B10's bureaucrats being petty to spite Nebraska for stealing their thunder. Same could be happening here.
I would think (a) or (b) is more likely than (c), but who knows. We'll know when we know.
Go Vols!