More than just this, I think they are trying to test things out with their telegram.
I am already on their telegram group and I see some users their mentioning that they are from bitcointalk forum. You known when you exploring some options reaching and retaining new customers you want to make it as calculated as you can be to prevent you from losing it to scammers who are already like a virus everywhere.
The BetHog team should take their time. The goal is to remain a reputable and sustainable crypto casino, not to hurry into the casino market, and fail because they made the mistake of making uncalculated moves due to pressure.
If the team has calculated and consider certain factors and have decided to keep it a closed group for the now, it is the best decision then because they know what they have under considerations, we just hopefully expect that it does not remain that way forever.