I agree with all of your points. As it happens, there was a highly-technical irregularity with this year's election that might have been grounds for complaint. Neither of the bids was concerned about it, but had even one member raised it as an objection, the BM would have had to take some sort of official notice and maybe even reopen the election, and since the results had already been made known, this would have created a huge kerflufle. (This is one of the few good reasons I've heard for embargoing the results until the next day's meeting; however, it's effectively impossible to maintain the embargo without locking the bidders in a room all night -- something we actually did in 1991 for Worldcon, but for a different reason.) As nobody objected, no official notice had to be taken of the irregularity (site selection had not been open enough hours on the last day of the election).

There's one other reason for scheduling that meeting -- if you don't, then you have to keep site selection voting open through the next-to-last day of the election, rather than only going two days as we did this year. As the bidders were content to have only two days of balloting, it was easier for everyone if we just did things the way we did.