It says clearly on their website that it’s not a fully random process. They shape it based on estimated completion time and preferred starting time, partly to make it a spread of ability and partly to make logistics easier at the start and the end. So if you put an ultrafast estimate and a first wave you’re clearly much more likely to get a place than if you put a middling finish time and a later start time.
If people really want a place it would appear there’s nothing to stop you manipulating your chances based on that information.
I’ve done it once, in 2015, and as far as I can recall that was the only year I tried for a place. And for the record, it was one of the best times I’ve ever had on a bike, flawless organisation and a great day all in all.