It seems Inti Creates is working on another port of one of its existing games. A Gamstat Blaster Master Zero 2 PS4 Japanese PlayStation Store listing has appeared. You can’t see it on the actual store and Inti Creates hasn’t made any announcement, but the data is apparently in place for it. [Thanks, Gematsu!]
Gamstat checks the various recent listings to see when data for upcoming games and demos are added before they appear. How long it takes for these items to show can vary. For example, the Gamstat information for Patapon 2 Remastered showed up at the end of December 2019, and Sony announced its debut at the end of January 2020. The Trials of Mana demo was found and shared by Gamstat in early February 2020, and the demo launched in mid-March 2020.
As for Blaster Master Zero 2 PS4, a port wouldn’t be completely unlikely. Inti Creates often brings its games to other platforms after a brief exclusivity period. For example, Dragon Marked for Death just arrived on the PC in April 2020. The original Blaster Master Zero started out on the Nintendo 3DS and Nintendo Switch, then headed to PCs.
Blaster Master Zero 2 is immediately available for the Nintendo Switch and PC.