I guess they are not publicizing the channel that much else a good project as this with a good community member figure aught to have more than the views as seen there and subscribers also
I think there are lot many investors also in the channel. Thats why they are not talking too much as if we see with the airdrop/bounty crowd. This also makes the huge difference in the telegram activity.
Most of the investors are not really chatting or talking on the community chat. Like on some possible investors, They preferred a silent reading and monitoring about the project because making an investments.