Maybe the Second Chancers will get a chance to become an eligible Housemate?
 

I could see there being a task or something like "you can walk away with 15k now or become a HM and risk leaving with nothing"

Or I could see the mass cull twist being that the Second Chancers can battle the original HMs to take 4 of their places, and the 4 unofficial HMs by the end of the week would be evicted or something messy like that