Or... like how insurance companies offer insurance if the mob burns your house down and will prosecute the culprits on your behalf.
If it does turn out that Microsoft is only doing this so that they can go and sue people who are using AWS or GCP then I'll change my tune. Until then I'll give them the benefit of the doubt.
Furthermore, if Google/Amazon _did_ follow suit it would be mutually assured destruction for Microsoft to sue AWS / GCP users.