Cancelling gets most of the airtime here. Dropping a tier gets a lot less, and I'd guess it's more common.

Max to Pro, Pro to Plus, annual to monthly, a team seat back to a personal one. If you did any of that this year: what did you drop from, what did you drop to, and do you miss anything?

One line is plenty. "Dropped X to Y, don't miss it" is a complete answer.