Typar is just the flashing tape and it is Butyl Rubber so 180 days is easy I would think.

 

pdf...
http://www.harveybp.com/Pro/docs/products/Typar_FlashingTape_specs.pdf

 

It looked odd to me that the foam board was cupping. The stuff we use doesn't do that so I'm wondering what product this image has.

 

looks like some Firestone insulboard we used to use for roofing...

Will the weight of the pour put it back in place?

http://www.firestonebpco.com/roofing/insulation/iso95/

 

The thicker insulation boards seem to cup more. I used seconds for my extension which were a fair bit cheaper. They went over the top of the rafters and were over 4 inches thick. Some of these were cupped. At that thickness the fixings wouldn't get them really straight, so I'm not sure if the weight of concrete would do it, depending on how thick the boards are.