I'm a PT as well and agree with the above replies. Your PT should be able to help you start working toward those yoga specific goals when appropriate, but likely could start doing some of the poses that aren't involving the shoulder. Finding a PT with a yoga cert would likely be your best route.
I've had a total right shoulder replacement 8 years ago. I agree with asking your PT for advice. I do pilates 4 times a week. And have for the last 2 years. I've also had two hip replacements. Shoulder replacement recovery is a long recovery I found. Best regards.
Get cleared by your Surgeon and a PT. I teach Yoga and Pilates, I would recommend pilates over yoga after a joint replacement. Many Pilates Instructors with with PT's, it's more common than Yoga Instructor's doing so. Pilates is also more rehabilitative and could help you work towards your yoga goals, the 2 disciplines really compliment one another. Stay safe & healthy.