I have 500 hrs part 121 in another company and going to start soon as a near entry captain, if I get the 175 ( in case there are not too much cadets) am I still going to be displaced as soon as I get the 1000 hours part 121? Or am I going to have a seat lock position? Is there any advice before doing the move?

btw the bonus is 23k starting 8k after training and 10k after the year so far