2 different shipyards.
Rostock-Warnemünde is where the hull was started, and was sold and converted into a naval repair base.
The ship was moved to Wismar in 2019 which has been sold to Thyssenkrupp Marine Systems (TKMS) to build submarines. TKMS wont begin their operations until 2024 so they CAN leave the ship there as storage until that time. Of course, the objective is to sell it and re-hire the 950 workers laid off from MV Werften to help retrofit and complete the ship.
If they get a buyer that just wants to finish the ship as-designed, then yes they can complete that before the end of 2023. If it's
DCL, then my guess is the rework will add time to that but will also add $$$ to that, so they may be able to negotiate an extension, or by that point enough of the hull could be complete to sail from the yard, and complete the remaining work elsewhere.