Well I'm not a legal expert, so the answer to your question, could be a 'maybe'? I'd hate to rely on it being a different system, and not get an irrate response from Hasbro/WotC. I wouldn't mind publishing it outside D&D, but apprehensive about what is legally safe - I don't know...
As an aside, I did publish as an imprint under Rite Publishing, the
Kaidan setting of Japanese Horror (PFRPG), I own the IP, I share in Copyright, I authored some of the work. Despite it being Pathfinder 1.0, since I fully own it, I can re-develop and publish it for PF2, for D&D 5.1e, for OSE, whatever game system I desire to publish it for. Being that that is the case, and being that Kaidan as a Pathfinder 1.0 product won't get more development, as is, but I can certainly continue its development for other editions, and other game systems. Right now, I am contracting someone with extensive OSE development experience to do a conversion of Kaidan to OSE, so as to widen the use of Kaidan for players in other systems. I see a need for a GM's Guide and Gazetteer to Kaidan for OSE, an Advanced Players Guide to shoehorn in my Asian classes into OSE better, and a Kaidan Bestiary of 20 - 36 monsters (something that never got published, but is a definite need).
I also see myself creating some map set books with typical locations of Kaidan - ryokan roadside inn, yakuza gambler den/brothel, formal bath house and inn, a kabuki theater, a teahouse restaurant, a rural shrine, an urban temple & garden, a samurai walled manor, yakuza gang house, typical mercantile shop, a kimono and silk dyer shop, a weaponsmith, a typical rice farm and home, a border fort. I could also see a book of exotic maps locations for Kaidan, like my undersea sea dragon city of Ryukyo, a lord's castle and palace grounds, a wilderness village of henge and tengu, a Kappa pond and underhill complex, an isle of the dead (for undead encounters). Of course these latter books would be compatible with any Asian fantasy game system and setting.
So Kaidan is an easy and legally safe conversion. Arcane Armada is less so, in my opinion.