The strategy for scalpers now appears to be get in as fast as possible and buy as many tickets as they can. But if we can assume the event will sellout completely and there is sufficient demand (e.g. Taylor Swift which I think I read would need to do 900 concerts to meet the initial demand) then scalpers could still win. Scalpers would just need to set a desired amount of tickets to buy and attempt to buy them at the last possible moment. They will get the tickets for the cheapest price for the event and could then sell them for a markup.
I think people would buy the scalpers tickets since they may have been waiting to see how low the prices can get, or they are able to obsess over remaining ticket numbers like a bot could and just missed out.
The only benefit I could see to the Dutch auction is it increases risk to scalpers by making them pay larger prices and get the last pick of seats, but only for events with allocated seats. So maybe instead of half the tickets for an event being scalped, they may only have the risk appetite for 10% of the tickets.