Answer: No.
Step-by-step explanation:
The Sherman Antitrust Act of 1890, later amended by the Clayton Act (1914) prohibits agreements in restraint of trade and monopolization. I expressely outlaws competing firms to conspire to consolidate the market by unfair means, restraining the trade of others.
In this case, the standards for non-wood bats set by the NCAA and the NFHS are not meant to establish a monopoly and they don´t restrain Marucci´s trade.