Microsoft giving these credits to OpenAI doesn't mean some other customer won't buy the Azure credits they planned on buying. So I don't see how what you write makes sense.

At least assuming Microsoft hasn't run out of capacity in their data centers. I know Azure sometimes have capacity issues but those issues are intermittent and not say 5 year long (or whatever the windoe is when it comes to consuming these credit)

So when they give you $100 in free credits they are losing $100.