This is the only game in the original trilogy releases that has never been released without DRM. As seen with companies occasionally delisting old titles, and a decent modding scene for the old version of Mass Effect 3, it would be such a shame to see it poofed out of existence when EA decides the world no longer needs it. The Legendary Edition of ME3 is ultimately a remaster, running on a newer engine and with revised lighting, sound mixing and rendering.
The original "master" of the third game must be preserved, even if Multiplayer depends on EA's servers, and will inevitably be closed within the next 10 years.