According to a reddit post (with a picture of an internal document regarding onsite training for Delta SkyMiles changes) Delta’s SkyMiles program will be making changes on September 14, 2023. At this stage it’s unclear what these changes will be but some other rumors include:
Changes to SkyClub lounge access
Transition to a single point program for elites (e.g MQM, MQD, and MQS are all combined)
Feel free to share your guesses in the comments below.