Mother 3 is deserving of an English localization, but it's unlikely that Nintendo will ever bring the game to the Switch, or any other system for that matter. Mother 3 isn't the only game that's deserving of an official English release, while also being unlikely to receive one, thanks to a number of different factors.
The diehard Nintendo fans want to see Mother 3 localized, but it's unlikely to happen. Nintendo has never explained why this is the case, especially following the popularity of EarthBound on the 3DS/Wii U Virtual Console. One theory is that it's due to characters in the game called the Magypsies, who resemble offensive LGTBQ+ stereotypes, but Nintendo has never confirmed this.
The following games have been fan-translated into English, but they're only available through illegal means. This is an age where games can continue to earn money through platforms like the Nintendo eShop and Steam long after their initial release, and they deserve a chance at winning over international audiences.
Bahamut Lagoon Has Had Fan Translations, But No Official Ones
Bahamut Lagoon is a tactical RPG that was originally released for the Super Famicom in 1996. It was originally meant to be called Final Fantasy Tactics, but the decision was made to distance it from the Final Fantasy series, and that name was given to another game. Bahamut Lagoon was translated into English by fans during the age of SNES emulation, and fans realized that they had been deprived of an amazing game. The world of Bahamut Lagoon is composed of floating islands where an evil empire is battling for control of the land. Like similar games, Bahamut Lagoon lets the player use parties of adventurers with their own character classes and special abilities, but the big draw is the dragons. The party has access to a number of dragons whose form can be altered with items, changing their appearance and powers in a manner similar to Pokémon evolutions. There is a slim hope for a localization/remake of Bahamut Lagoon, as Square Enix has been revamping its back catalog in recent years. The only potential issue is that Bahamut Lagoon isn't connected to any of Square's big franchises, so it's likely on the bottom of the pile.
Radical Dreamers Is A Japanese-Only Chrono Trigger Sequel
Most fans are aware that the classic JRPG Chrono Trigger received a sequel on the PlayStation, called Chrono Cross. There was a Japan-exclusive sequel to Chrono Trigger, which could only be downloaded through the Satellaview peripheral. The game was called Radical Dreamers, and it starred Serge, Kid, and Gil, who would later appear in Chrono Cross. Radical Dreamers was a text adventure title, which followed the main characters as they attempted to steal the Frozen Flame from Viper Manor. Many elements from Radical Dreamers were repurposed for Chrono Cross, and it was originally planned to appear in Chrono Cross and the DS remake of Chrono Trigger as an optional extra, but it has yet to be re-released in any format. The creator of Radical Dreamers mentioned in the Ultimania Chrono Cross guide (via Chrono Compendium) that Radical Dreamers was half-finished, due to tight deadlines. If Square Enix decided to do a Pixel Remaster of Chrono Trigger or a remake of Chrono Cross, then Radical Dreamers could also be revived, and the original creator could be brought back on board to flesh it out.
Mother 3
There was a time when there were a number of games that fans badly wanted to see released, but thought would never happen. As time went on, this list grew shorter, with the mythical FF7 Remake, Shenmue 3, and Duke Nukem Forever all being playable right now. The last white whale on the list is Mother 3, the sequel to the beloved EarthBound and the one game that Nintendo fans will hound the company about until the end of time. Mother 3 is widely regarded as one of the best RPGs on the Game Boy Advance, and a remaster/remake announcement would dwarf anything else mentioned during a Nintendo Direct. Nintendo fans will keep holding their vigil for Mother 3 for as long as it takes, but Nintendo has always been resistant to the idea of releasing the game, and the day may never come when fans will be able to experience the game on Nintendo Switch.
Source: Chrono Compendium