"одна баба сказала" (c)
Does this Matsapulina realize, that when you install Telegram on new phone, you just need to confirm the phone number and all your chats are restored on that new device? So for authorities to read her chats it's just a matter of intersepting an SMS with the confirmation code?
Of course, I suggest everyone to assume the software they use may be compromized.
But let's not post trash articles. In the article's own words, "conspiracy theories, paranoia, and speculation".