Sounds like a good idea in general but why would someone use a Telegram bot when there are already Telegram channels you can join for the same signals? The thing about bots is it's an additional security vulnerability users won't want to have (or I won't rather). UNLESS you can setup the bot for custom signals!
Or unless that bot wanted to have subscribers and then slowly turn it into a "paid" trading signal bot. No offence to the OP, but it is better to be skeptic at this point and as what others have said, trust needs to be earn.
Maybe you can keep up with this thread and at least show us some trade that you yourself did using this bot so that we can see how effective this bot is. Best of luck.