In the Decemver Cleric Playtest document, the road map has two Monster related bullet points, one for new Monster stat blocks and another promising revised encounter guidelines. Not a lot of explanation on what that means, but theybare looking to overhaul the guidelines in some fashion. The latest playtest revised the road map to be just PHB focused, promising the MM and DMG changes will be looked at after thenPHB is mailed down, so who knows what's going on now.
I doubt they will change the overall framework, but the guidelines for Encounter building will change.