Making minor changes in bowling technique can fall apart under the pressure situation of a game at any level. A player will tend to go back to what he knows best and makes them feel comfortable, back into old habits. It's why international players only ever seem to change techniques as a result of injury, or during times when they are out with an unrelated injury. You can't be heading into games still trialling something like a technique change.
I'd imagine that when you've completely remodelled someone, taken apart their action and pieced it together again piece by piece, you need to reinforce that until it becomes human nature, and they have complete faith in that technique. The purpose of not playing cricket, in my mind, makes complete sense in terms of actually enforcing the change and making sure that the bowler has faith in it.
Of course, talking about 7 years out of the game, etc. I don't ever proclaim to know how long is reasonable, whatever. But there's a greater need to actually refine the action and make sure that the bowling action is fine first of all, then exposing it to game day only once it is ready.