Doesn't seem like there's any consensus on what "cold" means in this context. It's strange to me, for instance, that someone would stop riding when it's in the 40's Fahrenheit. That's still risk-of-overheating temperature IME. Impactful or unpleasant cold doesn't come into consideration until it's below 20, and the cutoff for riding at all for me is closer to zero (-18c). There is usually a spell of a couple weeks a year when it doesn't get into double digits here in New England.

There's also no standard for what the article considers exercise. Going out for a walk is exercise, after all. Is the article implying people shouldn't walk in the winter? It's possible to ride a bicycle without exerting much more than a walk (if you have access to level terrain).

I dunno. The article just seems like click bait.