Two points. 1. Perhaps several large sellers submitted their...

Two points.
1. Perhaps several large sellers submitted their acceptance on the same day and off market. Perfectly acceptable and above board.
2. Why would a days delay matter anyway the offer is still open so anyone who wants to can sell. No one is disadvantaged whatsoever.

Looking for shadows when you don't get your way is not helpful. This is all lawful. Just because most have sold against the uprampers opinion doesn't make it wrong.