Here's the wording from the SEC Document (pages 78-79) itself for those interested: (emphasis mine)
In addition, Activision Blizzard has also agreed that, except (1) as expressly contemplated by the merger agreement; (2) as approved by Microsoft (which approval will not be unreasonably withheld, conditioned or delayed); (3) for certain actions or omissions that may be taken in response to COVID-19 (following reasonable prior consultation with Microsoft); (4) as required by applicable law or regulations of applicable stock exchanges or regulatory organizations; or (5) as disclosed in the confidential disclosure letter to the merger agreement, during the period of time between the date of the merger agreement and the effective time of the merger (or earlier termination of the merger agreement), Activision Blizzard will not, and will cause each of its subsidiaries (with exceptions for certain specified joint venture entities and the extent of Activision Blizzard's obligations with respect thereto) not to, among other things: ...
... voluntarily recognize any labor union, works council or similar employee organization or enter into a collective bargaining agreement;
All I have to say is just yikes... $75 billion dollar union busting from Microsoft...
Sure, MS can technically approve the unionization but it's still just gross and I'm pretty sure we all know that they probably will not allow it...
Probably explains the excessive amounts of union busting going on recently as well
Also: unrelated to the rest of the OP, I know my title is a bit wordy, if anyone has any requests to make it less wordy let me know so I can ask a mod to change the title