Observant fans have reported that Square Enix plans to remove the classic versions of Final Fantasy V and Final Fantasy VI from sale on Steam. The Steam page for both games now warns that they will be pulled on July 27, and it encourages fans to purchase the newly-revealed Pixel Remaster versions when they become available.
The Pixel Remaster versions, if you are unaware, were first announced during Square Enix's E3 press conference this year. Releasing for only PC and mobile platforms, these are more visually polished versions of the first six outings in the series. No release date has been announced for these remasters, but we can't imagine that it will be too long after Final Fantasy V and VI are pulled.
Thanks, Siliconera.