Vault-Co has printed this same assertion many, many times over the years. The reason we have always qualified the statement is the same reason everybody else does who knows the truth.
We'll just print it in plain english.
Most canned foods are perfectly good after fifty years in storage.
Sure, we could add a big list of disclaimers after that to protect ourselves. Obviously, if it doesn't smell right, looks moldy or has changed color dramatically, well then ... but seriously, think about the implications. You probably thought you had to purchase all freeze dried to put any long term trust in your stocks. Hell, many freeze dried foods will likely go two centuries stored correctly.
You have to learn some basic rules. Acids and sugar syrups can go off, fruit juices will spoil quickly for this reason, many other qualifiers can be tacked onto this knowledge.
Still - a really good thing to know and rare to hear anyone commit to.
Wherever possible, keep it cool, dry and in the dark in sealed conditions. Oxy absorbers beat everything when it comes to extending shelf life.