Honestly a time window is standard practice to prevent customers from potentially holding the ability to negatively review as leverage.

For example if they were to allow indefinite periods for reviews, then customers could hold off on reviewing for a year, then leverage it to get the seller to provide out-of-warranty service.

Not sure what their time limit is, this is the case for it. In any case, good customer service still means a human reviewing and deciding if it's appropriate at the edge cases of policy.