Dreamer, a diagnosis is useful for access to things like hormones, but not always necessary for that, either, depending on the doctor writing the prescription. My doctor does want the diagnosis on the HRT recommendation letter. YMMV.
Beyond that, the diagnosis doesn't do anything but establish a medical stake in the ground that may be useful in the future by showing a treatment trail that may be needed for insurance (provincial coverage in your case), etc. If you ever move to SRS, you will need multiple diagnoses, one by a PhD or MD - at least that's what the standards of care call for.
No SRS? No need for a diagnosis, though some find it validating. It doesn't define you. As a medical pronouncement, it's nothing more than a partial view into who you are.