We haven't heard much about the Seiken Densetsu games since the recent remake of Seiken Densetsu 2, known in the west as Secret of Mana, was released
a little over a year ago. Before that, it was nearly two years ago that the collection of the first three games in the series was released for Switch, only in Japan. However, it seems like there might be life in the series again as Square Enix Japan have now filed for trademarks in Japan for "Collection of Mana" and "Secret of Mana," which is a little bit odd given that the "Mana" names were never actually used in Japan until now.
"Collection of Mana" specifically seems to echo the Japanese name for the Switch release, "Seiken Densetsu Collection." Could that mean that an official release in English of Seiken Densetsu 3 might finally be on the cards? Or are Square Enix merely looking to protect their IP more globally? We don't yet know, of course, and Square Enix are certainly not yet saying. Given that other Mana-series trademarks have recently been filed in North America and Europe, it could go either way.
Source:
Gematsu