Yes it is required for Indian travellers not anyone else I believe. I was mentioning this since most in this thread are from India as it seems(cause direct flight ban). So UK path is not viable for them. No issues for others tho.
OK, I understand now.Yes,Indian citizens begining their journey from India to Canada have to arrange testing for themselves in the last third country.
This link confirms this rule:
https://travel.gc.ca/destinations/india
So,me personally,as an Indian national residing in Europe for years, I am currently neither affected by the flight suspension nor by this testing requirement by Canada
But,I personally advise that the route through UK to Canada, which I suggested earlier, must be avoided at all costs, by anyone in this forum, who will be beginning their journey from India.