I think a lot of the connections will become more relevant over time. They've been very careful with how they've words some of those tidbits for the fans. I think as Marvel Studios begins to expand their portfolio of films, and projects like Black Panther or lesser known characters like Runaways, Luke Cage & Ka-Zar start to be released, you'll see a fleshing out of those details to help contribute to the larger story being told across the different films. One thing I've really liked so far is that they've managed to make a series of films that connect together, yet have different feels and approaches by themselves. Iron Man has that tech/Batman edge, TIH had a Bourne style to it, Thor went with the Shakespearean family drama and Cap went for that WW2 serial approach. With Ant-Man said to be a mixture of 1960's and present day stories, that'll bring a different feel to the group as well (something that First Class, IMO, did well- though they took the 60's Bond approach, and are said to be doing the 70's next, which gives a nice sort of alternate history to things).