There are two approaches to determining citizenship: where you are born (jus soli – this holds in the US), and who you were born to (jus sanguinis – the case in India). There are mixes of these systems, such as where a person born to an American but not in the US is still an American citizen (e.g. Ted Cruz). Canada allows Canadian citizenship to be inherited outside Canada by 1 generation, so a child born outside Canada to Canadian parent born in Canada is a Canadian citizen. A child born outside Canada to Canadians born outside Canada is not a Canadian citizen. If that child is born in India and the parents do not have dual citizenship, the child is stateless because at least one parent has to be Indian to acquire Indian citizenship at birth.
There are various exceptions to the generalization about only revoking citizenship with dual nationals. In 1962, about 20% of the Kurdish population in Syria had its citizenship revoked. Albert Einstein was stateless for 5 years, after he renounced his (German) Baaden-Württemberg citizenship. There is no law in the US that prevents you from renouncing your citizenship, there is simply a particular formality that has to be followed. Wikipedia names a half-dozen US citizens who relinquished their US citizenship and had no other citizenship (thus were stateless).
The Japanese Nationality Law limits dual citizenship and requires children to make a decision at age 22. Iran, however, prohibits renunciation of citizenship to the offspring of an Iranian male (it is automatically assigned to the child). A Japanese-Iranian child born (in Japan) to an Iranian father would might seem to have to become Iranian; but apparently Japan requires you to perform the act of renouncing, and does not require that the other country recognize the renunciation. The point is that renouncing citizenship involves the laws of two countries: the country that you renounce may or may not accept the renunciation, and the country that you renounce in favor of may or may not accept the renunciation.
Section 10 of the Norwegian Nationality Law exemplifies a further variation in concepts of renunciation as part of gaining Norwegian citizenship, and statutorily acknowledges the problem or countries not allowing citizens to renounce citizenship. There is a requirement of naturalization that "the applicant must be released from any other nationality before the application may be granted", which also allows that it's okay if you can be so released after being granted Norwegian citizenship: or, ultimately, "An exemption may be granted from the requirement regarding release if release is deemed to be legally or practically impossible or for other reasons seems to be unreasonable". (The law in Norwegian is here: a Norwegian lawyer would be better able to comment on the interpretation of the text, but my reading of the law, especially the requirement to be "løst fra annet statsborgerskap", specifies the realized result of being released, and not the act of renunciation, hence "release" in the translation).
If a person has dual US-Ukrainian citizenship, they might symbolically renounce their Ukrainian citizenship to avoid an expected revocation of US citizenship and deportation to Ukraine. But the US has no law that says that it must recognize the renunciation of a foreign citizenship. Canada and Australia do not allow you to renounce your citizenship if it would result in statelessness, but not all countries have such a requirement. See for instance sect. 9 of the Citizenship Act of Canada:
Subject to subsection (2.1), a citizen may, on application, renounce
his citizenship if he (a) is a citizen of a country other than Canada
or, if his application is accepted, will become a citizen of a country
other than Canada...
There is, however, no specific law that compels Canada to recognize a person's renunciation of some other country.
So whether the described strategy would have any effect depends on the extent to which the "retained" state is compelled to recognize a renunciation of a foreign citizenship.