The creator of the Telegram messenger did not change his attitude to the WhatsApp messenger and highlighted that it could be dangerous for private files of users.
In May 2019, Durov even advised stopping using the service at all due to the range of vulnerabilities in WhatsApp. He also said that those problems can appear again and multiply in future.
Relying on some unmentioned sources, last week Durov informed that there are new security problems which make the private life of WhatsApp users public. The new owners from Facebook seem not to intend to fix existing bugs and provide the hitch-free working.
Actually, Pavel compared operating of WhatsApp with the well-known Trojan virus. Users should be aware of the spying ability of the program and try not to share their photos via chats. Plus, users should remember that WhatsApp uses external servers to store data. Especially when the messenger became the property of the Facebook company, it's more likely that government agencies can observe records or can be snatched by hackers.
Mr. Durov is sure that Facebook tries to confuse people when saying that to verify the presence of vulnerability or confirm the hackers' break-in, the company experts need to analyze data. And that will violate the privacy policy; thus FB doesn't do that, keeping up with a rule: "there is nothing to analyze, there is no evidence".
Anyway, it's up to you to decide which service to use or whom to entrust your data.