Normal people wouldn't think so but to a lawyer "any matters that arose or may arise directly from the investigation" is a hole that a Mack truck will fit comfortably through.
Way too much lee way to expand the scope, especially with liberal lawyers that have an axe to grind. Under that guideline, Mueller might as well go back and investigate the business dealings of Trump's father, and grandfather, how many diapers Donald soiled as a toddler during a 24 hour period, did any of his stool contain traces of Russian dressing, when, why, how, and to whom did he lose his virginity? Was it to a Russian?