Square Enix has trademarked Collection of Mana in Europe ahead of their E3 2019 media briefing. It is a trilogy containing the first three Secret of Mana games that was released for the Nintendo Switch in Japan.
Collection of Mana trademark is not a new thing as they have also trademarked earlier this year in Japan. This trademark was filled in Europe (via) though, so it is different in that sense that either it is for a new game in the Mana universe, or perhaps Square Enix is planning to launch the Secret of Mana collection with this title in the Western markets.
Since this trademark was filled in Japan as well where they have already released the collection with a different name, it is looking more likely that this will be a new collection of Mana games. We won’t know more until E3 2019 if there is an announcement planned for it.
The original Seiken Densetsu collection on the Nintendo Switch features the first three games in the series. The third one was never localized for the West officially in any capacity which is why some fans were hoping to finally see it get a localized release.