Yes I do believe that it could. I believe that a major or even near-total (much less total) collapse of decentralization is a technical failure, and is a possible (and not outrageously implausible) outcome of BIP 101.
I agree that a major or near-total collapse of decentralization would be a technical failure.
I guess we just assign very different probabilities to that happening under BIP101.
So much for the technical debate being "over."
In other words - The technical debate is over. There will be NO catastrophic failure of decentralization with BIP101.