I guess it's pretty hard to get an accurate idea of how many cadets they will take.And I don't think it's a good idea of even trying.
When my mate got it, on his assessment day, 4 type-rated on the Bus candidates didn't make the cut.On the day you have to be good and that's that.
I think that the 2% is a little off.However in the open day,they did mention something like 140 pilots,then tho FO on the flight I took with them the other day said 200.There are other A320 operators who offer bigger salaries recruiting at the same time,Wizzair won't be able to fill all of their seats with experience just like that,my two cents..my be wrong.
There will be more slots.Now,in regards at how they filter candidates,then I cannot comment as I have never applied online with them.