I approach it like the time travel in infinity war: Marty traveling back in time creates an entirely new timeline where he and doc meet up in 1955...alternate reality.... multiverse can be applied to anything really

I see (not just here) and hear people lamenting how a "classic" will be "ruined", which I wholeheartedly understand, as a devoted self described film/movie snob myself; however, nothing is happening to the original. It will still exist as is and if one does not like that another filmmaker is making an adaptation of Mary Shelly's classic, then that person does not have to watch that adaptation. It's as simple as that.

I personally am excited to see how Del Toro handles the work! It's widely known that he has great iration and respect for the book and former classic film, the James Whale version at least. And, given his attention to detail and high standards in his other works, I'm not too worried about this version turning out bad...

We shall see...