No.

Stale flour in good condition (no mites or other (generally harmless, but unattractive) creepy-crawlies) no obvious fungus or other signs of contamination, might not be a good long-term staple, but as an occasional ingredient in an ordinary healthy diet is quite harmless.

Its vitamin content probably would be slightly reduced, and it might be slightly bitter or (if whole wheat especially) slightly rancid, but if it is not a mono-diet, it should do no harm at all. If it is hermetically sealed, like some exploration rations, it still could be worth eating decades later, especially in polar conditions.