So, yeah, it appears that "Jim Ryan's burner account" was correct.
Just days after a particularly privy anonymous account hinted that The Last of Us Remake was coming out in September, the original game's director, Neil Druckmann, confirmed it himself at the recently-concluded Summer Game Fest.
According to Druckmann, a lot of work was put into remaking 2013's The Last of Us, which will come out as The Last of Us Part I. It's not just about making the nearly-decade-old title look better with more fidelity, but Naughty Dog also wanted to make sure that the remake would retain the essence of the original game as well. In addition to better graphics, The Last of Us Part I's AI is better and it will support 60 frames per second at launch with better controls. Also, for the PS5, The Last of Us will support PS5-exclusive features like 3D audio, haptic feedback, and adaptive triggers, amongst other features.
TLDR; The Last of Us Part I will be the true definitive version of The Last of Us.