They'd have to show at least one plane with a bearing gone that still flies as intended. I suggest we break one on purpose, put the full complement of Boeing execs on that plane to prove its safety given the alternative of retracting that statement.
That depends on the meaning of “safety of flight”. I don’t know what it means in aviation, but do not rule out that there is significant room between “flies as intended” and “result in a safety of flight condition”.
For example, if an engine were to complete drop off the plane, would that necessarily result in a safety of flight condition, or does “the plane will be able to continue take off and land again” mean safety of flight isn’t affected?
But a takeoff does seem like the worst time to catastrophically lose 1/3 power, even without FOD intake by the central engine.