There should be a way to limit what reps can select from in the product library. The property exists for Currently Active - Yes/No. But, it doesn't do anything. When a product is discontinued I can't delete it from the library, but I should be able to restrict it from being used!
I understand that you would like to hide some products from the library while adding them to a deal, currently, HubSpot does not have this capability, but this is something the product team has under their radar since it is a constant request from our customer, I will be confident in saying we should see something very likely in the future.
In the meantime, I would like to encourage you to upvote this idea here, which talks about this same request and where our product will eventually comment if there is any launch in this regard.