The initial plan did not include major endgame changes.
While Grinding Gear Games is developing Path of Exile 2 in an "early access" format, there will be no release in 2025.
Currently, Grinding Gear Games is aiming for a full launch of PoE 2 in 2026. During a conversation with PC Gamer, Mark Roberts stated that he would be "very, very surprised if the game isn't fully released in 2026."
The creators of Path of Exile 2 themselves did not expect the development to take so long. One of the reasons for the delay was the need to rework the endgame (this was not initially planned):
...We certainly didn't plan for the game to be in early access for this long. So we're now like, \"Okay, fine, we need to do this, we need to move forward, we need to release the game.\"