OK, watched it now.
I could see how they made the second Mrs DeWinter more assertive, perhaps due to the modern trend to centre stories on empowering women. Which is fine, and is to a certain extent what happens in the book.
But that is especially problematic when they glossed so briefly over what Rebecca did. It's dealt with in a couple of minutes, without all the detail on the extent of Max's devotion to Manderley, his care for his reputation, and the extent to which Rebecca taunted him about that. It came across as "she cheated, therefore she deserved it and she was dying anyway." The new wife finds her voice and uses it immediately to cover up the murder of her predecessor.
Keeley Hawes did the only bit of subtlety in her comments, giving clues to Rebecca's nature and how her beauty and reputation weren't all they were cracked up to be. They skipped the bit where she seduced Frank Crawley.
You could easily get the impression that it was happily ever after for the De Winters. But it isn't. They live an impermanent life on the continent, she has to very carefully manage his life so it is easy and safe etc... Not passionate snogging in Cairo.
For the record I don't believe Rebecca was a feminist saint either, but the fact is that her angry husband murdered her for her transgressions, and her force of character, executed by Danvers, takes his true love from him - Manderley.