1) France can't extradite its own citizens. So if US wanted him he would be arrested somewhere else.
2) A rumor is a rumor until it is officially denied, and it was officially denied by Macron, so it is likely that Macron administration ok'ed a high profile arrest.
3) It's not a backdoor only for the Russian government but for any government because secret police all over the world have access to SMS on any local mobile phone number (more complicated for them to hack︀ a foreign number but it can be done in many cases by using an old︁ flaw in GSM standards, namely advertising a foreign number being abroad, say in Russia, and︂ using roaming GSM standards to get access to SMS and Telegram/Whatsup/etc). For some very mysterious︃ reasons Telegram has always relied on that convenient mobile phone trojan horse and saved all︄ the chats on their servers unencrypted by default to give you (or your government's secret︅ police) access to your Telegram conversations from another device. For precisely these reasons Pavel is︆ also known as FSB Major General Durov in many countries. How a team of very︇ talented and educated developers ended up with an excellent messenger and at the same time︈ offered zero encryption by default and no alternative secure sign up methods - why do︉ you have to register via a mobile phone number? Many people, especially developers, think if︊ a messenger was designed in a way that is a gold mine for secret service︋ (easy access to conversations and easy deanonymization via mobile phone number) they must be controlled︌ by FSB/CIA or have some secret arrangements with them.
4) Auto moderation of content in︍ Telegram is bizarre to say the least. FSB has learned that all they need to︎ do to ban the channel or give FAKE icon to it is simply report this️ channel as illegal content from hundreds or thousands of their Telegram bots/trolls and voila is is banned or discredited with a FAKE icon. No way to undo it. So there is an "AI" moderation at its best which again give a reason to nickname Pavel as FSB Major General.
5) A leaked border crossing database indicates that Pavel visited Russia more than 50 times since his "exile", and some of his visits are very suspicious - for example he visits Russia and the next day Telegram is no longer blocked in Russia despite the court order to block it. So maybe at some day he︀ really started cooperating with FSB full time.
6) WSJ leaked that Pavel's phone was hacked︁ by French secret police as early as 2017. I guess they didn't learn much since︂ Pavel goes to Russia to talk with important people there eye to eye while being︃ in exile. He is probably one of the most valueble FSB assets, not just a︄ usefull idiot as mentioned above. I guess France wanted him to become a double agent︅ and he refused and denied any cooperation/secret deals with FSB and was arrested. Some people︆ say it is adding his TON crypto wallet in Telegram that triggered the arrest because︇ governments don't like crypto very much unless they control it.
