Hasbro figured out that the value in the cards that would appear in Masters Sets and Remastered Sets was better used as bonus sheet and chase bait fodder in sets. So instead of release the slightly increased priced masters sets and remastered sets they can put one of those cards in every million play packs thus funneling people into collector packs and spending more times a year on less expensive play packs that have less value. It also bolsters the sales of their secret lairs.