Why are Bachelor contestants allowed on Nick Viall's podcast?

As a podcaster myself, I can't tell you how many times I have been denied contestants to come on the show. It seems that anyone who is under contract can only go on Bachelor Nation podcasts, with the exception of Nick Viall's ,Viall Files (I think maybe Kaitlyn's Off The Vine too, but at least she hosted the show recently).

Nick is pretty harsh when talking about the contestants and the show, so why does ABC approve their contestants to go on his pod? Susie went on his pod the day after the finale. Same with Gregg Grippo.

Any conspiracy theories on why?