People who make whole wheat bread add gluten to improve the rise. That is to say, to get it to rise at all. It was marked down because it was outdated.
All food has a date, but it doesn't mean anything. Food stays good until the can swells, or for anything with shortening in it, until the package is opened. I buy outdated canned food whenever I find it.
Today I found canned veggies for 40 cents a can, but I have so much food I had to make a rule: no more food until I eat something to make room for it.
I make whole wheat bread at home. I am glutenous maximus.
Speaking of gluten, that is what makes your pie crusts lousy. The chemistry is rather involved, so I'll let you read it at your leisure. https://www.backwoodshome.com/articles2/blunt132.html