How some people know very early on what are the new crypto that will be listed on Binance, coinbase, kraken and others) ?
There is no faster way to communicate than the forum itself. I mean whenever there is emerging project then those project managers will have bounties and Announcement threads opened up in the bitcointalk forum. This forum forms the basis of all projects because this is the similar minded community. All you need to do is keep your eyes wide open in the Altcoin section and have regular updates.
Telegram is full of surprises. It do give us lot of updates but due to uncertainty of telegrams use anyone can create fake accounts and pose as if they are the genuine leaders.
Best way is to subscribe to their social media accounts when you come to know about them on the forum.
FYI: Exchanges like Binance, coinbase, kraken do give us daily updates whenever there is any listing or new project coming up their way.
This should be sent to you over e-mail. So better to subscribe into their news letter.