Why is everyone expecting or hoping for Deadpool in Avengers Infinity War?

I read this so many times. The first question is from where these people get the news or from where they get hints that deadpool and the rest of the MCU are even connected. Because I personally never read "I hope the X-Men are in this" or "I hope Wolverine shows up". Its only about Deadpool every time. Second is why do these peopl think that he even would fit into these movies? Am I the only one that is reading that the whole time? I seriously dont get it.