Update 5/8/2024: We have released a more updated Roadmap Update covering the future on-premises releases of Exchange Server.
In September 2020, we announced that the next version of Exchange Server...
Updated Feb 12, 2025
Version 4.0
Blog Post
Dear product team,
great to hear about the addition of MFA to Exchange on-premises in the future! Really awesome 
If you could even pimp the Edge-Server role to support DANE, then I would be a more than happy on-prem admin 
I can understand your move towards the "Modern Lifecycle Policy" which implicates great opportunities.
As an on-premises only admin, this change gives me some headaches because this could mean that when your assumption:
"We plan on continuing to support Exchange Server as long as there is substantive market demand."
is not met anymore (in theory no one wants on-premises), this would leave the remaining on-premises installations with only a 1 year timeframe to transition from Exchange on-premises to other products. Since a 1 year heads-up is a though one, this would mean we need transition plans from the next version of Exchange to another product, before we can even transition to the next version of Exchange, since we do not have any assured supportability. 