I finally met my new manager [1]! It's been … what? 3½ months? … since it was announced. I decided to ask a VP (Vice President) of the Corporate Overlords who was my actual manager, M1 [2] (who was promoted) or M2 (who is to replace the promoted manager). The VP said M2, and that since I have yet to meet him, I should invite him to the next department meeting. Why it should be up to me to invite M2 to our daily meeting and not M1 is apparently beyond my pay grade, but I invited him.
And it turns out the situation is still … complicated. M1 is still my “manager” for some things for the forseeable future, and M2 is my “manager” for the other things not handled by M1 for the forseeable future. But overall, the meeting went well. We shall see how things go.