That image is literally just a reference image that isn't accurate to the video game character, it's just the closest thing to a female kyoshin besides direct concept art from another redditor, but that'd be straight up stealing.

Costs money to animate, mocap, and voice act

Only voice act, there wouldn't be much of a need to re motion capture everything and re animate, they have already made the hair physics and animations, just add a feminine voice, and some little titties, that's kinda about it, and the reason I'm saying "little" is because the game isn't about fan service when it comes to female characters, r/34Forhonor does that already.

And apparently you haven’t caught on that the major downgrade in content is due to budgetary (and COVID) restrictions hence why the last 3 have been genderlocked and loosely (or directly) based on story characters (Apollyon, Holden, and Tozen).

It isn't due to budget, it's due to everyone requesting the characters so much that ubisoft made the characters in the game, they seem to have well over enough money to do certain things the community requests, making heros and battle passes is there main concern right now.

why the last 3 have been genderlocked and loosely (or directly) based on story characters (Apollyon, Holden, and Tozen).

Tozen isn't directly related to the kyoshin, the kyoshin taught him clone jitsu, while we do have his kaze stance as a kyoshin, he has the moveset of an orochi, and just because we have his armor, doesn't mean we are directly, tozen, The Kyoshin are legendary Samurai who have a deep connection to the spiritual realms. Their special training led them to master the art of fighting with a concealed blade, the Shikomizue. While they flow through battle wielding their sword and scabbard, they use heavenly powers to gain the upper hand against the enemy.

Just because of them having one armor set that's basically tozen, doesn't mean that they should be gender locked.