HBO shared a video across social media ( https://www.youtube.com/watch?v=o07u0uKkV_g ) revealing that a Harry Potter remake is being made. The message promised that it would be a book-accurate remake with a 10-year plan to ensure each season is dedicated to one of the novels. Of course, they must recast the actors, probably making some fans angry.
The teaser indicates many elements from the original movies will be present, including the logo, the Harry Potter theme, as well as the same design of Hogwarts. Of course, it's possible that once the series goes into production, these features will be replaced with a logo, musical score, and set unique to the HBO series. However due to fans love for the original movies, it would not be smart to tease this and then remove it.
There is also the Wizarding World theme park to consider. If they have to change parts of the theme park, the attractions would suck. The TV show will probably keep many of the aspects from the movies in order to keep the franchise alive. In many ways this is good, but depending too heavily on the movies could be a problem.
The decision to keep the memorable features of the movies is meant to keep long time fans comfortable for the new show. However, seeing the new actors may ruin the experience.
This will happen whether HBO borrows elements of the original films or not. By mixing the new with the old, the remake will probably not do very well in my opinion.