Model View Controller, in a game!?
I am no longer surprised by the constant change of requirements in games. Especially for UI elements.
Most of the time, it's not the data that should be changed however (it's not like they suddenly want the high score to be a label congratulating you on your progress) it's the presentation of it.
The odd case where the behavior is subject of tweaking also occur.
The kicker is that they want to do an A/B demonstration of the two variants, or maybe an A/B/C/D test.
It's pretty clear where I'm going with this right?
Make the model contain the data of what should be visualized. Then, implement a small controller where you control the rendering of whatever data that should be rendered. Then, have this controller configure and initiate various views for the data depending on some input that enable you (the rock star programmer) to change UI in run time with no hazzle.
The next time your boss changes his mind, you may even have the implementation ready.
In contrast to the web MVC model, I've found that the controller should be allowed to play a bigger part. It should be allowed to constantly control the state of the view, i.e. for helping with animations and transitions.
Good luck on your mini MVC for your UI!