I am little bit late to answer, but the pattern has already been broken. In Doctor Strange (2016) movie,
Time Infinity Stone was introduced
and its name is: Eye of Agamotto.. Only if its name was "Necklace of Agamotto"..
The original premise of the question seems flawed, by the way. As @CreationEdge said in the comment:
The original theory you describe was already about shoehorning the objects into "names" that fit under a THANOS acronym (and really I don't understand why they went with Orb instead of Hammer for Ronan's Hammer, but whatever)
Yeah, Orb and Scepter weren't actually named in-universe.
Maybe, pattern hasn't been broken at all. If in-universe name doesn't matter, we can call Eye of Agamotto necklace because it was really a part of a necklace.
Here's final take on everything for fans who want to believe in this theory:
- T: Tesseract (Captain America, Avengers)
- H: Hydra/ Home of Hydra (Avengers: Infinity War)
- A: Aether (Thor 2)
- N: Necklace (Doctor Strange)
- O: Orb (Guardians of the Galaxy)
- S: Scepter (Avengers, Avengers 2)
BTW, this isn't official.