This most likely means that Hideo Kojima and Masahiro Ito are working on an upcoming Silent Hill game, which is awesome news.

/r/silenthill/comments/fb0i1q/伊藤暢達masahiro_ito_on_twitter/

This is still great to hear and something I'll be HYPED for if it's announced. However, we should make the distinction that it's probably not the same Silent Hills that was cancelled. There really was no Silent Hills when it was cancelled, because it was cancelled so early in development. (P.T. was a standalone game announcing Silent Hills, not an actual gameplay demo)

For that exact game from 2014 to make a comeback, so many top creators/actors (including Guillermo Del Toro, Norman Reedus, and Junji Ito) would have to make room in their schedule. It feels like that was lightning in a bottle, and Del Toro and Reedus already went on to be involved in Death Stranding with Kojima.