Hello,
From the link above, I understood that it is only expected to be in production until 2029, is it right?
Yes, that is the case.

Is there already a time plan for extension yet? If not, could you kindly let me know until when will the extension decision be made.
That is always dependent on the demand from customer side. Right now it is in plan for 2029.
But if it is a new project I would look at S32K3xx devices as they are replacement of MPC5744P.
Best regards,
Peter