Does disabling iMessage read receipts stop me from receiving them?
The functionality is for messages to get delivered via SMS if that is enabled and iMessage is disabled or not available for the sender.

iMessage should / is designed to receive messages whether or not you are sending back read receipts as long as you and the recipient are on devices that match in Apple's database of recipients that are iMessage capable.

Something else is up - it could be related to the switch (as software corruption can act in weird ways) but it's certainly not the typical behavior.