I wouldn’t call this a new theory, it is an accepted theory. Damaged tissue appears, in some cases, to be prone to malignant cellular conversion.
Malignant melanomas are alleged by some to be caused by UV light exposure–however that theory ignores other considerations, like the incidence of malignant melanoma and locations of many melanomas.
Malignant melanoma is a bad boy. Best to have big or growing or ugly looking melanomas taken off and analyzed, and not just in the sun exposed areas.