That's one way to think about it.
But there's another way... A more optimistic one :
Assuming (the likely fact) that the volume/number of test invitations will go up in the near future (since the pilot of the online citizenship was more than successful), we could see a rapid change in the number of test invites sent out and the number of people invited for test per week. I am extrapolating this from the fact that IRCC managed to send 7 months worth of applications to IP in just 4 months.
When they start sending out bulk test invites, this backlog will go down, albeit gradually. IMO, early - mid 2020 applicants might see their test invites in the second - third quarter of this year.
I've requested a
bunch of corporate documentation from IRCC to see what they are doing to cut the backlog, among other things. I expect to receive this document sometime in March.