Welcome
Good question!
It's a "MYTH"
Any wood can be burned.
All wood needs to be seasoned & dry before burning.
Folks out west in the mountains have burned pine safeley for 100s of years.
Pine is a good shoulder season wood.
Yup. And parts of northern Europe,Russia & Asia have nothing but evergreens & have been burning them for thousands of years.Ya burn what ya got.Its all good.