I hear that deleted accounts tend to be reanimated there, and that people need to delete accounts over and over again, and never really get deleted. But merely flagged and made 'invisible'. The data never leaves the servers.
This also happened when Facebook bought Whatsapp. People who then opted out were also just flagged and disabled and not deleted. Back then it was a big issue that made it into dutch parilament. Yet a few years later the state started to work together with whatsapp and now even does free marketing for whatsapp by placing 'neigborhood watch / whatsapp signs' As the government chose Whatsapp as a nationwide system to rat on neighbours. And cause more conflicts then to provide actual solutions.