Yup, I've seen that. But people who want to fly to India soon after their oath have 2 options :ok, this is what I found now at https://www.cgitoronto.gov.in/page/surrender-certificate/
Even after acquiring the Canadian citizenship, the Indian passport can be used to travel for 3 months from the day of getting the Canadian citizenship. The grace period is only for such cases where foreign citizenship has been acquired but a foreign passport is not available to the person. It is also mentioned that it is illegal to travel on an Indian passport, where a person has obtained a foreign passport.
1. Use the Dubai option which is in the grey area
2. Try to get an entry visa (I heard this is being issued only for emergencies because of COVID)
3. Postpone the trip
Its up to the person to choose. I personally wouldn't choose option 1 unless I MUST travel because of a genuine emergency. It is important to plan your travel beforehand once you receive an oath invitation. Unless it is an emergency, do not travel to India without a passport and OCI.
That option was provided to explore the possibility, do your due diligence and then decide if you want to travel that way.