What value would they even really add?
At least with the Game of Thrones, it was the first time it was adapted to television.
In the case of LoTR, there's already been a big budget production that won a ton of Oscars.
This seems very strange to me. Usually these studios want to try new ideas and less conservative. This smacks of a typical Hollywood studio problem, just regurgitating existing franchises into new mediums.