US-made missiles are blowing stuff up inside Russia because Russia invaded a treaty partner who gave up their nukes in exchange for a security alliance with the US. And yet Russian apps are in our app stores. Nobody needs to imagine.
No servers in Russia. Given Pavel's prior history it seems unlikely that he would cooperate with Russian government. Plenty of other criticism of telegram is warranted but it's probably not a tool of the Russian government.
I would argue that Telegram is a much, much larger security threat to the average individual American than Tiktok. Except they comply with government search warrants and don't enable E2E encryption by default so they are useful to the American National Security Establishment and get to stay.
There are no Russian apps that collect extensive data on hundreds of millions of Americans. (And if I'm wrong about that, the US should absolutely force divestiture of those apps or ban them).