Abolutely. Period gear/weapons for a WW II game is not negotiable.
Could you get away with arid CADPAT instead of AOR1 at a modern game? Probably without a second glance.
Can you rock out a Multicam plate carrier and M4 with a box mag amongst a group equipped with Grease Guns and M-1s? Nope, not ever.
Airsoft, where nothing is hurt but feelings.