"Organizations often treat symptoms because causes are politically difficult.
In a dependency upgrade with unknown blast radius, the conversation keeps returning to what you do not know. The practical question is what you will do anyway.
Under pressure, vague plans become brittle plans. The cost shows up later as rework and quiet blame, because no one can point to the chosen tradeoff. Be honest about what would change your mind, because without a revisit signal every decision becomes permanent by default. Clarity is not certainty; it is a small commitment the team can execute without reopening the decision at every update.
Surface the assumption the plan depends on and name the first signal that would prove it wrong. That is how you keep pressure from rewriting the decision. Stop while it is still simple.