I think the quality control at the M & M factory is abysmal. I got a pack the other day and about half the bag was filled with Ws. Simply appalling.
I had a consulting gig at M&M many decades ago when they decided to do a Xmas special with Red & Green M&M's with mint flavored chocolate. They were awesome IMO and yet they never did it again. Go figure!
I'm pretty sure I've bought mint m&ms during the holidays. They are yummy. Coffee nut or espresso m&ms are my other favorite. Chocolate, coffee, and mint flavors mmmmmm!