Personally, I don't get mad or upset whenever a remake, readaptation, reimagining, etc is announced and made. I like seeing reinterpretations of stories. We get revivals, so why can't we embrace movie re-adaptations? The original films will always be there, and you don't have to watch the new movies. We readapt Shakespeare, Austen, Dickens, etc. Why can't the same be for film? Also, I wasn't born when the original West Side Story or Mary Poppins were released. It has been thrilling watching these classic musicals get reinvented in my lifetime. Finally, similar to the Disney live-action remakes, I love seeing stories delve deeper than what their originals did. I loved that the Cinderella remake spent the first 25 minutes or so basically being backstory by explaining Cinderella's childhood, how her parents influenced her personality, how she came to have a stepmother, and how she became a scullery maid, while the original movie told all that in a 2 minute prologue.
All that to say is I think it's fine for old works to be remade again. The new Little Women was so good, the Lindsay Lohan Parent Trap is pretty much a classic, and I hope this West Side Story retelling will be its own classic one day.