After 3rd December 2019 it has been made mandatory to all.Biometrics is on a case by case base. I received the automated mail for biometrics for myself(inland) and spouse(outland) in 2019. Paid for it but I was refunded mine and my spouse's biometrics was requested and submitted. 2months later, they asked for our medicals and original police certificates from out of Canada.
So, I don't think biometrics is compulsory esp if you've been in Canada.
They have put the exception for now only for Temporary resident visa, student visa and extension, for Inlands.