TFT Set 3 release date is confirmed, but it has a release window of mid March 2020.

TFT Set 3 Release Date

On March 12 at 3 p.m. PST, Riot will be hosting a showcase event for the Galaxies Set. We could expect to see the new set release shortly after this showcase event.

Today is the day! The TFT Galaxies Showcase starts at 3 PM PT!
Here's a quick look at the players in Group A! #TFTGalaxies

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— Teamfight Tactics (@TFT) March 12, 2020

Galaxies will be the third set for Team Fight Tactics, and features new space themed Origins and Classes. There are new champions as well: Mana-Reaver Thresh, Cybernetic Ekko and Starship Aurelion Soul. Aurelion Soul in his Mecha skin is the first Starship Champion.

Starship Champions won't be able to basic attack, but they will circle arena and deploy fighters to attack as long as they're around.

If you want to give the new Champions a try, there is an official team builder by Mobalytics for Galaxies that you can use to get ready for the next set.