No, they don't. It would cost a lot of money to design, manufacture and distribute a lefty based camera and stores would be reluctant to carry them as they would need to allocate shelf space for them.
Please understand I do not mean to be condescending but the operation of a camera even for lefty's is quite simple. I've never heard of a lefty frustrated at the need to use their right index finger to take a picture instead of using their left index finger.
I have found several patents for the idea but none have made it commercially.