Before talking about the American adaptation; i'll refer to the original Japanese Horror classic, Ring.
Ring was made in 1998; where It was made off the Japanese Novel, Ring. It garnered a sequel one year after in Japan. The film itself, used prominently of a VHS Tape that at the time; made sense; considering that DVDs we're a large thing until the early 2000's (Even though they started in 95).
The Ring, in essence; is based off of a dated IP, that unless they do something innovative in Rings (the upcoming American sequel); it would be useless to incorporate it into the event. Regardless if it may be Iconic in some aspects.
Also, I think personally on a level; Ring is one of those films that may not appeal to everyone, and would be in ways; a much more riskier IP to incorporate into the event like (if not to me, more) the film of Killer Klownz from Outer Space.
Its one of those films to me that wouldn't make sense, and would possible not get as much as of an appeal unlike other IPs that would be much simpler to incorporate into the event.
That's my personal opinion, and I know that a lot of people will probably give me crap for saying it; but in my mind, I think its an IP that has quite a bit of Red Tape that may not be feasible for HHN.