Top review on the 2nd version you posted says this:
"For some reason, EA delisted the original version of Mass Effect 2 on Steam and replaced it with a newer version that seems identical in everything except two aspects. Firstly, it now includes all DLC, which previously required you to buy them on the EA launcher and then manually download and transfer them to the Steam version. This process was not intuitive, but now it's all included at no additional cost and hassle-free. Secondly, it now requires the EA launcher, which is annoying but not a huge deal in the end. However, it does create a situation where we have two nearly identical versions of the game in our libraries, which is a bit odd. I suppose this could've been an update instead."