I understand your ask for PTZ, but I would make an educated guess that rumors about a Meraki PTZ camera are rumors. There will be other camera models in time, but I seriously doubt PTZ will be the next one to ship.
Here's an earlier post I made for same question in an earlier topic, hope this helps!
https://community.meraki.com/t5/Security-Cameras/PTZ/m-p/1259#M46
Industry reports show decreasing PTZ camera use, and Meraki is not likely to add a PTZ camera to the portfolio anytime soon. Less than 10% of cameras are PTZ, and PTZ cameras can be 2x to 3x as expensive, they are physically larger, and heavier (motors/servos) and these moving parts wear out and break down more frequently, and the more you use it, the shorter its lifespan becomes, as indicated by the shorter warranty typically offered on PTZs. PTZs do have their place in the industry. But perhaps the biggest drawback is that if you PTZ into a specific area, the camera cannot record what it isn't looking at.
Most PTZ use cases can be addressed with proper planning and multiple non-PTZ cameras today, and in the future with other models that might offer a wider field of view for example. There are many cases where PTZ cameras have been deployed and then the pan and tilt functions are rarely used, and only the zoom gets used, to zoom in for identity or zoom out for overall scene context, and MV does offer a varifocal lens remotely adjustable via Dashboard for that purpose.
All that said, MV cannot address every use case. If you're in retail and want to follow an active shoplifter around a store, the MV cannot be used for that purpose. But I'd make the argument that with well-placed cameras and Dashboard's video wall, you could get very close, as well as meet all other retail requirements.
MV21/71 are the first two products in a new and exciting product family. Help Meraki help you, keep making wishes in Dashboard, and keep the feedback coming through your Meraki sales team or Meraki Partner so all of the use cases and feature requests can be collected, categorized and prioritized.