Earlier quoted context omitted.
I would hope that a billion in credits would not represent a billion in expenses for Microsoft.
They're giving up all the profits from whoever they would have been sold to otherwise. So it adds up the same.
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)