It's easy for people within each club to find out who is looking and talking to who. Most players have agents, one way of securing a better deal for their client would be to inform interested teams so and so are also talking to the player.
With confirmed, but unannounced signings, they'll all go through the league for registration and Simms obviously knows Smith quite well and probably works in the same room as him when in Sheffield. It's probably as simple as opening an excel document for him to find out whose going where.
You could bet that Lord, Kelman knows who Steelers are looking at, who Panthers are looking at, Who Giants are looking at etc.. but the word professionalism suits the Devils and most other clubs very well, something which can't be said about Steelers. Be glad that your team is focusing on itself rather than what is going on around the league!
His periscopes are generally quite good, he's there live and often sat near a computer or has his phone on at all times so it's a lot more reliable than reading his often rude tweets.