After reading that mishmash of rumors, hopes, and creative interpretations, it would still make no sense to bring Warlock into the IW movie. They'd be trading all the work they've done to build Thanos, plus Vision, and what, replace all that with some convoluted Warlock story that sounds a bit silly to actually say out loud? Maybe it's because I'm not a Warlock fan, but I just can't see them bringing Warlock in at this point. I think that the cocoon in GOTG means as much as the Howard the Duck cameo did.
Right, because Warlock has no connection to a cocoon at all. I'm sure it was just a giant alien butterfly the collector was collecting.
According to James Gunn, that was simply an Easter Egg. There's every chance that he's meant to become more of a player, but they could just as easily leave the situation be and only a few diehards would notice.