Older versions don't support it, so if you run a newer Primary expecting the support with an older Secondary that doesn't, the metadata will fail to get sent no matter what you do. (Well, you can remove the Secondary, but that's pretty nasty.) This change makes the check more tolerant. If there's a problem with verifying the Root metadata (especially if an intermediate Root was skipped), the verification will still fail, but now at a slightly later phase (which is where it would've failed before).
Older versions don't support it, so if you run a newer Primary expecting the support with an older Secondary that doesn't, the metadata will fail to get sent no matter what you do. (Well, you can remove the Secondary, but that's pretty nasty.) This change makes the check more tolerant. If there's a problem with verifying the Root metadata (especially if an intermediate Root was skipped), the verification will still fail, but now at a slightly later phase (which is where it would've failed before).