I don't think that the new upgrade rules will have much negative effect for high level elites. On popular routes they don't release many O bucket seats in advance anyway (my experience lately has been 4 days unless the flight is really wide open). They then run the CP/PP sweep; I guess there might be a small window in the wee hours where a mileage upgrade could sneak in ahead of the sweep? The effect on GP/SP upgrades could be more pronounced however.

We will see.