I don't think that there is something wrong with it, and it doesn't mean that this project is 100% a scam. Now projects have migrated to telegram as it is more convenient, so there is no need to update BTT thread. This is normal.
I agree with you. Failure to renew the BTT thread originate from its failure to follow. If there are those who follow this thread, he will give an opinion about the lack of innovation. In the other hand, this place has lost much in its old value. Without signature campaigns, thousands of people would leave.
But telegram is very useful in this regard. It offers the opportunity to track innovations, learn people's thoughts, and ask any question and it is easier to use.
But we also know that they are one step away to running with such doing. Without updating their BTT thread is a sign that they are not responsible for their job. BTT recognize as one of their way to reach their community/investors. Even if they can communicate using telegram channel, they should still update every detailed progress in every channel including BTT to show that they are working and they are reaching everyone.