Polaris being Magneto's daughter hasn't been retconed away in the comics. As for whether the show will use that connection or not, the franchise has such a mixed track record with how it treats X-Men characters that Polaris on the show could end up being Nightcrawler's daughter and I wouldn't be surprised at this point

In the comics, Polaris was raised by her mother and (I think) a step/adopteddad who she didn't know wasn't her real Dad, so they could start her out with normal parents but have Magneto being her dad be a surprise reveal if they wanted.