The source for that (https://archive.ph/OONbb - WSJ), as far as I can understand, made no claim that MS owns IP to GPT, only that they have access to it's weights and code.
Yes, there is a big difference between having access to the weights and code and having a license to use them in different ways.
It seems obvious Microsoft has a license to use them in Microsoft's own products. Microsoft said so directly on Friday.
What is less obvious is if Microsoft has a license to use them in other ways. For example, can Microsoft provide those weights and code to third parties? Can they let others use them? In particular, can they clone the OpenAI API? I can see reasons for why that would not have been in the deal (it would risk a major revenue source for OpenAI) but also reasons why Microsoft might have insisted on it (because of situations just like the one happening now).
What is actually in the deal is not public as far as I know, so we can only speculate.