Looks like Final Fantasy 5 and Final Fantasy 6 will be vanishing from Steam next month to make way for the upcoming Pixel Remaster versions.
Both games now have "(Old ver.)" tacked onto the end of them, with a note in the description that reads "this game will no longer be available for purchase after July 27, 2021. Instead, please purchase the pixelated remaster version," (thanks, Kotaku).
Honestly, this is both good and bad news. The Steam versions of Final Fantasy 5 and Final Fantasy 6 are hot garbage, visually and mechanically. Ugly, vectorised sprites that are blurry and feel out of place against the maps have been a major criticism for both games. They're also rubbish ports, plagued with bugs and very clearly built for use on mobile phones. There are plenty of visual overhaul mods to try and make them better, but they're widely considered inferior versions of excellent Final Fantasy games.
On the other hand, it looks like we might be losing out on some stuff. Both games include content later introduced when they were released for the Game Boy Advance. Final Fantasy 5 has four additional jobs, while Final Fantasy 6 has all of the extra content from its Nintendo iteration. Judging by sprite comparisons (via RPGSite) and Square's page for the game, it seems like the extra goodies won't be present in the Pixel Remaster versions.
While the Final Fantasy Pixel Remaster covers the first six games, it seems like it's only Final Fantasy 5 and 6 that are getting the chop. It makes sense in a way—the first two games aren't on PC, while the Steam versions of Final Fantasy 3 and 4 are the far better-received 3D remakes that were originally on the Nintendo DS.
A release window of July 2021 was recently given for the Final Fantasy Pixel Remaster, but for some reason, Square Enix has since set the video with this information to private. The ever-attentive Wario64 has collected screenshots and info from it though, saying each game will release individually starting next month.