Nah those are legit different things.

The sympathetic/parasympathetic disregulation probably responsible for some MECFS cases is a different mechanism from the immune system disregulation probably responsible for others. Though, it is unlikely that just general stress would get you MECFS, you’re probably burnt out, which is also a real thing but different.

Key question: do you have an effort limit, and will surpassing that effort limit cause your body to revolt (sometime within the next ~24 hours) as well as lower your effort limit for future episodes?