While submitting the application, the ircc website was showing "wait till you get the medical request". And even the hospital refused citing the same. Most probably, It was to avoid the chances of re-medical, in case, it expired before the application got finalized. God knows when they will send the medical request now?
https://www.canada.ca/en/immigration-refugees-citizenship/services/immigrate-canada/express-entry/documents/medical-exams.html
still says -
If you and your dependants are outside of Canada
Don’t get your medical exam as soon as you get your invitation to apply.
We will send you a form telling you when and how to get a medical exam.
When you apply online, you must submit a letter of explanation in your document checklist instead of your immigration medical exam (IME). In the letter, you must indicate that the primary applicant or the accompanying dependants of the primary applicant are outside Canada.
If you have undergone a medical exam as part of an application in another category and/or if you have completed an IME in the 12 months before you apply, you can submit a copy of the information printout sheet or the IMM 1017B Upfront Medical Report form in your application.
An IRCC officer may still require a new IME.