People who can't prove their loss of citizenship in many cases can't naturalize as Estonian citizens. Estonia doesn't allow dual citizenship, however currently there are ways to bypass this. It's a known fact that there're citizens of Estonia who are over 18 years old and hold multiple citizenships and are not forced to give up any of those by Estonia. Another known fact is that if you are granted international protection you don't have to prove your loss of citizenship when applying for Estonian citizenship. It doesn't matter why these 2 examples are completely legal. What matters is that it means that Estonia effectively allows dual citizenship in certain cases because of certain exceptions from the rules.

Citizenship is just a legal relation between an individual and a State. If an individual swears to never return to the country of origin and never exercise its relations with said country anywhere in the World - it's no different from an individual who was granted an international protection.

I suggest Riigikogu to consider exempting people from the certificate of loss of citizenship for people who don't have any plans to maintain any form of relationship with their country of origin and ready to face the consequences if they break such promise. In this case the act of promising (by signing relevant papers) to never exercise relations with the country of origin should be considered as an equivalent of declaration of loss of citizenship.