Update []: This has now been confirmed! Tony Hawk's Pro Skater 3+4 launches day one on Xbox Game Pass on July 11th, and is said to "faithfully remake" the two games from the ground up while also adding new skaters, parks and music.
As expected, Iron Galaxy Studios is the developer behind THPS 3+4, who you may recall for their work on Killer Instinct back in the Xbox One era, and they take over from the now-defunct THPS 1+2 developer Vicarious Visions.
A Career Mode that includes the original tours from both games will be present in 3+4, as will cross-platform multiplayer that supports up to eight skaters at once. It's mentioned that a NewGame+ mode is part of the package along with new creation tools, while the gameplay is said to "build on the work" started in Tony Hawk's Pro Skater 1+2.
Interestingly, the trailer you see above features a brand-new 'Waterpark' level that's described as a "broken-down, dried-out park in the heart of the Mojave desert", and we're assuming we'll learn of more new additions in the near future.
Just to follow up on the details mentioned below, the Foundry demo will be available in June for anyone who pre-orders the game (aside from on Nintendo Switch), while early access will be offered to Deluxe and Collector's Edition buyers. Xbox Game Pass members who want the Deluxe Edition content can pay £18 / $18 for a special 'Upgrade' version.