The whole minibar 'enhancement' is a huge fiasco for IHG / RA. For such a small cost (compared to many other potential top-tier benefits), it truly separated RA from the rest of the field. Free minibar - no questions.
If it is indeed the exemplified "minibar abusers" that has triggered this change, then enforcing the existing rules would have been more than sufficient to stop it. I quote from the current T&C:
"Beverages are complimentary from the mini-bar in the Royal Ambassador’s personal room only, and for in-room consumption by member only (benefit excludes non-beverage items)."
Simply put, if the empty bottles are nowhere to be found in the room, then the hotel has every right to charge the guest. Period. Obviously, I would assume that any hotel with a bit of 'fingerspitzengefühl' would look the other way for the occasional missing coke, beer, miniature vodka bottle etc. (who doesn't enjoy "one for the road" every now and then?), but cracking down on the obvious abuse would be easy enough. It would of course upset the guests in question (mostly because their behaviour has been exposed) - and perhaps even target some guests wrongfully - but overall the word would spread fast and the practice would cease to exist.
(Should have been) End of story.
Instead, they create a lot of unnecessary bureaucracy, for both the hotel and the guest. Plus they just couldn't control themselves when coming up with this 'masterplan'; they just had to implement a cost-cut with the USD 200 cap, which does nothing but to reveal the true nature of this 'enhancement'.
It will be interesting to see how each hotel decides to implement this rule. Will they turn to fine print and start charging for the excess coke (USD 3.50) or will they look the other way when the total minibar bill exceeds USD 300?
Time will tell.