According to Dutch law, you lose your Dutch citizenship if you accept another nationality. The Dutch embassies (who are responsible for renewing Dutch passports abroad) are well aware of this law and have processes in place to refuse a passport renewal if you can’t provide proof of temporary residence in the country you reside in. The local institutions however, don’t have these processes in place and are generally not aware of this law because it only happens to a tiny little percentage of the population. And nobody updates the national registry with your new nationality because that’s the responsibility of local municipalities, not the Department of Foreign Affairs. So if you decide to simply renew your passport in the Netherlands instead of abroad, they’ll just give you a new passport because you’re still registered as a Dutch citizen at the local level and they don’t have a process in place to check your foreign nationality.

Don’t ask me how I know :) It is one of the few accountability sinks that doesn’t affect me negatively.