This is just another example of card companys trying to "create" scarcity within their sets to sell more product. In the '50s, '60s, and early '70s, high-number baseball cards became scarce genuinely. Sets were released in increments that extended beyond the baseball season, so many collectors had moved on to collecting cards from other sports. In 1952, Topps dumped all of their high-number cards into the river because they weren't selling. Eventually, Topps would learn to manufacture less of their higher number cards--hence the genuine scarcity.
Now, it's become sort of a fad for card companys to make short printed cards within their base sets. Personally, I don't think a set is complete unless you have all of the base cards. Card companys are hoping to prey on people with that mind set. I'm still trying to find a way to complete the short-printed 2002 Topps Traded #1-110 cards. Some people will psyche themselves into believing the short-printed cards aren't really part of the set so that they can sleep comfortably at night, but those missing cards will always be there haunting you.
If a card is numbered the same as the base set, then I feel they are part of the set. That was a tough pill to swallow in completing the 1972 Topps set, and is even tougher in trying to complete the 1966 and 1967 Topps sets.