No. Player-made GUI's made for the current hud would have to be fixed to adjust to both HUDs, or be in a position where either HUD doesn't cover them. It'll just cause too much pain.
Games with Playermade GUIs would have to update their *PLAYERMADE* GUIs that they worked hard on to make it so it fits with the old HUD and new hud. Or they'd have to make a script that allows the GUi to cange between the two.