I don't even think it's possible to bald in the neck, at least not from male pattern baldness. I honestly can't see any hair loss in your neck to me it just looks like your natural pattern + a bad trim from your barber.
It kinda just looks shorter than the rest of your hair. Either your barber fucked up or it's thin and it's the beginning stage of alopecia areata (doesn't necessarily mean it's gonna get worse). Maybe you just have a weird density pattern. Surely not male pattern baldness.
