Given your example of a company unwittingly adding GPL code to their proprietary code base, I have trouble seeing how Microsoft can offer to take liability for

Given your example of a company unwittingly adding GPL code to their proprietary code base, I have trouble seeing how Microsoft can offer to take liability for such an infringement. The GPL requires that any software based off of it be GPL licensed and have public sources available. I can't imagine a situation where Microsoft pays a fine, and their customer gets to violate the GPL license by not removing the infringing code, or open-sourcing their product as GPL and providing sources to the public. Enforcement of the GPL can't just involve paying a monetary settlement to get away with stealing open source code. It must involve the direct targeting of infringing software with demands that the software either take efforts to remove illegally borrowed code, or license the borrowed code as legally prescribed by the original license agreement. That an AI got in the way of reading the license agreement should not be an excuse for doing zero due diligence in maintaining a lawful code base.