That would be nice. I'd personally like to see Coulson in a movie again. Unlike what Joss Whedon seemed to think, even casual fans could easily accept Coulson showing up in a movie. A single line could do it. Hell, its as easy as
Tony: I thought you were dead.
Coulson: I got better.
At this point its not like the Avengers would break up because his inspirational death didn't stick, and we've seen such crazy stuff in the MCU that people probably wouldn't even bat an eye out of someone being alive, and if they cared at all its just an easy google away. If its just a cameo it wouldn't matter if some people didn't know he hadn't stayed dead.
I doubt this will happen, but it would be nice. An AOS cameo in Infinity War would be mind blowing.