Presumably yes, depending on what's in the legal documents. I am guessing that Microsoft will transition slowly, in order to provide continuity to the Azure customers. But OpenAI will not "thrive" from this deal anymore. Partnerships tend to only work when both sides are interested, regardless of the agreements. If OpenAI needs several more $billion to train GPT-5, this will get sabotaged.
The scaling party is basically over. Or rather, it has moved to Redmond.