There was a recent post on the Poke2++ Reddit talking about the IV feature and it suddenly missing from the tweak/app. The post states the below. 

Well, here it is: It is unlikely that MITM will be solved for non-jailbroken devices. There are simply too many limitations given the recent changes by Niantic and what is required to solve them. As the data is basically now behind a wall internally within the application, it is a lot harder to extract the data that we require for IV and other associated MITM functions within a non-jailbroken environment as Apple also limits what is possible. This is not to say that we will stop trying, but the outcome is not looking favorable.  

So basically we most likely won’t see the IV feature coming back to unjailbroken devices. Yes this is a a big bummer seeing that the in app IV tool is basically junk. But this is the limitations that we have for nonjailbroken devices. The upside is the tweak has a fully working IV system for jailbroken devices. So all we need is a jailbreak to come out and we will all be happy.