I guess if Leanna gave us direct confirmation of something, like them never having sex, or her version of the breakup in general, it would be very interesting to hear. However, while 2016 Phil was pretty pathetic, he was at least a human being. Current Phil is much more detached from reality. So the best interview would be Kat.
Kat confirming that Phil believes all the crazy shit he currently says (why they can never take a vacation, why they can't go to Seattle, what they actually eat every day and/or do they DoorDash everything, do they have any contact with his parents or her sister, did Phil make up all of her health problems that he told the Casino or was she really very sick, does Phil actually work out, do they sleep in separate rooms and/or never see each other, do they really do power walks to the woods during his breaks to feed the woodland creatures, the list goes on) would be the real interview. Though if you ever listen to Kat, she's super-dented, so I imagine she's either brainwashed or she believes these things even more strongly than Phil does.