Video games being updated and changed is hardly anything new. 99% of games released now have Day 1 patches to fix things developers didn't have time to finish, and games with a dedicated multiplayer vein are always being balanced and tweaked on an almost weekly basis, all to make sure fans are satisfied with their playing experience.
Some video games however, have had content removed for many reasons beyond simply making the game "better" or "fairer". Developers (especially when making games in the late 80's and early 90's) often come across legal trouble when innocently using celebrity likenesses or making harmless in-jokes which come back to bite them.
Restrictions through the laws of certain countries deal with what content media and video games can depict or actions the player can carry out, with certain developers/publishers/series hitting this roadblock more than others (I'm looking at you, GTA). To a lesser extent, some material is often edited to reach a lower classification rating, broadening the potential demographic the game would be available to.
You also get a few anomalies from time to time, forcing a bizarre or seemingly innocuous alteration that could've prevented a title's release altogether.