Main idea of the testing questions is to check if an objection is valid according to the Holacracy constitution, not to discard the proposal.
If the objection is valid, the next step of the IDM process is integration: amending the proposal until it both addresses the proposer's tension and erases the objector’s objection.
About your topic, note that the complete question, if you know previously that the objection is anticipated, is: « Is there a reason we can’t adapt once we get more data OR Is it safe enough to try, knowing we can revisit that any time »
If the objector answers "Yes, it not safe enough to try, because we can't adapt once we get more data" and can give a grounded example of how the proposal could harm the circle, the objection is valid (at least regarding the known data criteria). That means that both objector and proposer will have to amend the initial proposal until it becomes "safe enough to try", even without known data.
Hope that helps,