For Canadian doctors: on breast augmentation. Can this be covered by OHIP as reconstructive surgery?

I’m not a Canadian plastic surgeon. It is unlikely any insurance company is going to cover breast implants and a genetic female due to having small breasts.
You should be able to contact the insurance nerwork and ask them what their insurance coverage criteria are.
Almost all medical insurance companies, whether run privately or by the government are based on some contractual guidelines.
Procedure authorization is usually associated with a justifying diagnosis code.
I suggest contacting some local plastic surgeons in your community though I think it is highly unlikely your desired surgery will be authorized.
Doing so opens the floodgates of every woman wanting breast enhancement.
Best,
Mats Hagstrom, MD