Speaking as someone who has hair similar to SMG's -- you can infer a certain thing about me from that -- I noticed that Burnam's hair was not Vulcaned but still straightened before her prison stint, but no longer in Context is For Kings.I think XCV330 put it best that Burnham's hair was probably more due to Sarek's influence on her and less (if at all) about Vulcan society itself. I mean, I think Burnham would have probably used that hairstyle if she were white.
I liked that and the fact that Burnam has kept that style for two reasons: 1) it was realistic that a prisoner would not think about or have the means to straighten her hair, and 2) after her parole, it was a small indication that she is embracing her humanity.
I have, however, silently bashed whoever the hairstylist is for making even Burnham's "natural" hair look fake -- especially in the later episodes of season 1.