To my mind I think that is as-designed and has a valid use case. A common practice would be to show “all patches currently applicable given the policy settings”, but this is really just a preview for sanity-checking the policy, not to see what applies on a given set of devices.
The use-case I see most often, is to create a policy and then define a schedule for that policy targetting a specific set of test devices. After the first schedule is applied and tested, it is common to add a second, or even a third/fourth schedule, to target larger sets of devices.
You may not have devices applicable to some of those patches in the first round of schedules, but as you add more devices and more schedules more of the patches get applied.