Agreed, this is an insane requirement. Our app uses commercial libraries from closed source vendors, some of which are no longer distributing newer versions of their libraries. If this becomes a requirement, we will not be able to ship our app because we can't deliver the entire thing in bitcode.
> Our app uses commercial libraries from closed source vendors, some of which are no longer distributing newer versions of their libraries
This is the insane part - you're relying on things you have zero control over and zero support for. Apple's requirement is no different than some fatal bug discovered or backdoor discovered in those libraries - except Apple is giving you some notice without immediately putting the liability on you.
That's not so much of a bitcode problem as a vendor problem. You'd have the same issue when 64bit builds became mandatory, or when uidevice.uniqueIdentifier was banned.