Transitioning Customers from a High touch to Low touch model

Have you ever had to move clients from Strategic CSMs to a one-to-many or low-touch team?  We are needing to do this with a very large portion of our customer base. Some of our lowest ARR accounts and ICP accounts were previously receiving a weekly call, now, quarterly will be the maximum our team can support.

What communications did you send and/or best practices have you followed?