I recently got rid of eight of my older hens who were two years old. Some still laid pretty good others not so good. Introduced at the same time 18 new pullets to the remainder of the flock. The remainder consisted of 22 road island reds, 11 months old. The road island reds have really slowed production down, today I only got 2 eggs. Could it be the stress of this change slowing them down? They lay pretty good throughout winter.
Welcome to the board! Yep, stress can cause them to stop laying just like you are seeing. If the introduction was very fast, and none of the birds knew each other though a fence for a few weeks, it may take a few weeks for pecking order to become solid and egg production to gear back up. Good luck!
I've had new birds take up to 2 months before they starting laying again ...first it was a month of quarantine away from my flock and then another month getting use to the new coop and hens...
Welcome to BYC forum! Yes, they might be surprised because of the loss. They will start laying as time goes. I had a chicken family of 7 chickens and when I got rid of 5 of them, the remaining 2 suddenly grew very quiet and inactive, but later on became well and happy again. Good luck!