while that is true, past incarnations of MJ have all shared several characteristics. MJ has been white, red head, and pretty.
Taking race out of the issue, MJ has been defined by her signature red hair and she's always been a pretty girl - whether she's the cute, nerdy "girl next door" type from Ultimate comics, the classic party girl from 616 or Spectacular show, or even childhood best friend from the Ultimate show.
MJ is also usually portrayed as friendly and outgoing and playful. Sure, classic party girl MJ is more extroverted than nerdy Ultimate MJ. But brainy Ultimate MJ wasn't some introverted bookish girl who sits off in the corner and makes fun of people with dry, sarcasm.
And no version of MJ ( as far as I can remember ) has ever been portrayed as a plain, frumpy looking ugly duckling who needs to undergo a transformation into a beauty.
If Zendaya is indeed playing MJ and we got a glimpse of her in the trailer, then that would be such a radical departure from the character - not just in terms of overall look but also her personality and potential story arc. If anything, it's the antithesis of what MJ's character type is supposed to be. To the point it feels like a totally different character.