I don't think that media will degrade more, if the initial burn does not scan as well as media x or media y.
You could have a perfect scan ( as already said on this thread) that degrades in days (ala G05's), and you could have a poorer scan that will last for many years. Longevity is unknown for ANY media. You don't know if you have a good or a bad batch, and you can't be sure the bonding will last. They only way to prevent (and you cannot prevent this entirely) is to buy high quality media, have a backup on more than one type of media, and check for degradation regularly.
How about an optical backup, and an image file backup of the disc on a hard drive?
Another factor is the type of burner you are using, and the type of drive you are using to scan. There are known scanning issues with BenQ drives scanning LG burns (IIRC) and Lite-On scans burnt on Pioneer drives (due to the burning relinks)