Just caught up with this, lots of cool tidbits about Reality Fracture:

• Tam is an artificial person created by Jace to be his spy in the regular Multiverse
• Tam's card includes an unnamed mechanic that represents Jace in his role of The Theorist, that they've described as "really crazy"
• Reality Fracture is described as "Planar Chaos"-like but will NOT break the color pie
• Hexhaven features 5 ally-colored schools that mirrors the enemy color schools because people kept asking for more Strixhaven schools
• There will only be a single Commander deck for Reality Fracture