Here in the UK I am insured to drive vehicle A as specified on my insurance documents. If I modify that vehicle my insurance policy is void and I need to inform the insurance co. and probably pay a premium.
In your scenario the same could be true on a software update.
And it wouldn't be unreasonable from the insurers point of view, since any update carries a risk. What's going to happen I think is that insurance companies will probably need to vet the updates before allowing you to install them, much like android phone vendors. Running un-authorized updates will void your policy.
Here in the UK I am insured to drive vehicle A as specified on my insurance documents. If I modify that vehicle my insurance policy is void and I need to inform the insurance co. and probably pay a premium.
In your scenario the same could be true on a software update.