false representation
fraud
knowingly concealing material circumstances
These are serious accusations here, we must not launch such serious accusations like that, lightly. Even by insinuation. This is very serious.
There is not, to my knowledge (Or maybe, very rare) documented case law where people have seen their citizenship revoked on a simple return to the country of origin. Examples on canli? ( link ). You will surely not find any.
More often than not, the rare documented cases of citizenship revocation speak of fraud, or lying, formally supported by evidence.
The fact that the former refugee has become a Canadian citizen in itself is a change in his personal situation, and may (not always) provide him with a semblance of protection if he undertakes the adventure of returning home. Some third world country (and indebted) states can be very careful and delicate when it comes to arresting or to hurt a citizen of a G7 country.
UNHCR guidelines, too, urge against revoking the citizenship of former refugees.
These are non-binding guidelines, but it it's relevant to mention, I think.
The observation page of passports issued for former refugees makes no mention of countries to avoid. (Apart from the general recommendations, of course, which can be found on the website ''travel advice and advisories by destination'').
https://travel.gc.ca/travelling/advisories