Nothing inherent to TPM gives MS more control over your computer than they already have. Honestly, it's more for storing your own encryption keys securely.

One thing I can see them do is using TPM to lock your Windows license to your motherboard. They already lock those, but I think they use things like the Ethernet controller's MAC address and other pseudo-unique identifiers to fingerprint the motherboard. I haven't dealt with TPM in a while, but it probably gives them a way to get a more reliable unique fingerprint that's harder to falsify. That would be a good reason to require it from Microsoft's perspective in order to ensure their revenue.

Nothing inherent to TPM gives MS more control over your computer than they already have. Honestly, it's more for storing your own encryption keys securely.