I also read the article today on a online news journal. I'm also from Bangladesh, I also use the same method to sell the bitcoin or eth if I ever need money. Last a year a group of people was arrested for selling and buying crypto if you remember. I used to sell my bitcoins to them after that news I was so afraid that I had to deactivate my facebook profile to keep myself safe. When the situation came to normal I came back to facebook.

So, again with this case I don't think anything will happen to people like you and me who used to sell a small ammount of btc to them. If the worst happens we may asked some questions from them nothing else.