So far, I have not found Microsoft’s plan for ActiveX controls in the future. Maybe you could wait and see if there is an alternative.
As tag "office-visio-itpro" means general issues of Visio, but your issue is more about the development of Visio that uses Drawing Control, to better help you, I would suggest you post a new thread in Office developer community.
There are more people with rich development experience, and maybe your questions could get more replies.
Thanks for your understanding.