It depends on what the message of the member there. We can see the difference if their message is real from people side, or just to fulfill the requirements of a telegram campaign. So pay attention to what the chat is about.
But telegram is not a factor about successful project
Agree, you can not determine whether the project is successful base on telegram activities. There are some projects successful with low and silent community, and there also successful projects with with shillers to make the community alive but most of the time, those TG groups with some loud noises and pure spam messages are scams.