The mail clearly says to not to do an upfront medical as it may delay the process. Section pasted below -Hello folks,
Is it worthwhile to wait for re-medical request from IRCC or do an upfront medical (after responding to the ultimatum email)? Will submitting an upfront medical report shorten the waiting time to receive PPR for expired COPR holders.
Important: Do not do an up-front medical examination. Completing a new medical examination before IRCC asks you to will delay processing, and may lead to you spending more money to do a new one later on.