I get that you don’t want IW involved in Halo but your understanding of how company acquisitions work is incorrect.
Yes the deal is being looked at by regulators and until that process is complete then Microsoft can’t tell IW what to do but as soon as that process is complete, provided the acquisition is not blocked then they own them and can have them work on whatever games they want.
I’ve given you examples of this within the gaming industry and I have first hand experience of this myself. If you don’t believe me that’s your choice but research it for yourself or speak to someone that has real world experience of such acquisitions and the regulatory investigation process.
I’m happy to get in touch directly to explain the end to end process if you’re genuinely interested in learning about it but I have no interest in you telling me I’m wrong about something that used to be my job.