Diamond benefits not announced yet so I will make another suggestion (may have already been made by somebody else):
Premium i.e. faster internet speed as an obligatory benefit rather than just the standard throttled speed set by each hotel (varies according to each hotel's own internet infrastructure or policy).
Seems like some/many hotels may already do this for Platinum members as indicated at log in but I almost always get what seems to be the standard speed for every room.
Of course this would not be necessary in hotels which already offer extremely fast speeds of 80 to 220 Mbps as I recently experienced in one Mercure.
But a few hotels in the same city seem to throttle their speeds at 6 Mbps. Admittedly there is nothing I cannot do with that sort of speed but faster is always welcome in accordance with the particular destination's internet infrastructure.