Even days or weeks is insufficient. If I buy tickets to an event four months from now it is usually incredibly easy to arrange an affordable flight, for example. Or if two mutually exclusive events I am interested in have tickets go on sale at the same time right now I can pick one and purchase a ticket. If they are sold out I can pick the other event instead. With this system if I enter the auction for only one and do not win then I am screwed for the second one as well. If I enter both auctions I run the risk of purchasing both tickets.
I can imagine some other, more subtle planning issues that arise as well. Not that the system couldn't work but I think it would make for a terrible standard model.
As a sort of side-note you talk about helping the artist extract some of the money they are leaving on the table. I don't it's fair to assume that they are leaving the money there because they can't figure out "hey, if people are successfully scalping then I could make more money by charging more!" They have to look beyond a single transaction and keep in mind lower income fans that they still want to please, for example. Such fans would inevitably lose the auction for any show that sells out but some of them actually get to attend the show with the current structure.