It's still not decided if it will come for P3D as well.
The initial plan was to make it for P3D V5 but, since the original post on Simultech Facebook page was dated March 2020, it was reported by some media to be for P3D4, since at that time P3D V5 wasn't officially announced yet, but we planned to use some features that are only possible with V5, like PBR on ground textures.
However, during testing, we found it was basically impossible to run it together with OrbX Cityscape Honolulu with a video card with "only" 8GB of VRAM, because more of half of the available VRAM was already taken by the Default + OrbX scenery, and this was even before loading a complex aircraft and after lowering graphic quality quite a bit in the settings.
Considering how difficult is today to buy any video card, of any brand, with more than 8GB of VRAM and how insanely expensive they are ( assuming you find one ), releasing for P3D V5 would probably mean nobody would be able to use it without a DXGI crash and, of course, releasing for P3D V4 only + MSFS wouldn't make much sense either.
Note that, we couldn't fit the scenery in memory even BEFORE was completed. We'll surely try again once it will, perhaps the latest version of P3D V5 available at that time might handle VRAM better but, if nothing changes, I doubt we'll be able to magically squeeze the scenery in half of the memory we normally have, because the other half is taken by OrbX.
The problem with P3D5 and VRAM handling has far greater repercussions than what most users suspect. You all want to use OrbX ( because the default scenery is not very good ), you all want to use complex airplanes ( which are the point of using P3D ), but if there isn't enough VRAM left for the *airport*, it doesn't leave much room for us airport developers to...do the airport, which you rightfully expect to be way more detailed than it used to be in 2010, when the old version came out.
So, at this time, the only thing I can say is that, once the scenery will be completely modeled, we'll try again if it will fit in VRAM in P3D V5, using a complex airplane and at least one scenery in that area from OrbX, with the V5 version which will be available at that time, that's the only thing we can promise to do.