Security between a stolen ipad and my iphone

My ex stole my ipad a couple years ago. At the time I panicked signed into find my ipad and it was turned off. So I erased it I think i rapped on the lost button and removed it from my list. And a month later changed my icloud password. I have since had 2 iphones and thought i was safe from sharing my pictures to this ipad. I realized soon after to turn off the photo streaming as this sends pictures to all my devices. And now recently iphone has changed to icloud pictures where it automatically shares pictures with all your devices. And it hit me what if every picture i take is being sent to my ipad he stole. Could he be snooping on me for a couple years? Is changing a icloud password enough for your icloud photos not to be sent to another device. Is removing an ipad from my list of devices enough to cut off all ties between this ipad and my phone or any new iphone I get in the future? I recently just changed my icloud password again and signed out any device including my new ipad using that icloud. Am I stuck with never knowing that all my pictures are being sent to my old device he has.

Any insight is helpful thanks.