Yes, it's very dated. Dated and downmarket.
And
Max as a nn is so stereotypically "self-conscious tomboy." Whereas
Sam for
Samantha,
Bobbie for
Roberta,
Dani for
Danielle seem natural and uncontrived,
Max for
Maxine,
Frank for
Frances and Mikey for
Michelle just scream "Look at me! I'm the heroine of this new kids' book! I sneer at girly girls and I never want to grow up! I'm thirteen and I still want to make mud pies! I throw a fit if I have to take a bath!"