honestly it’s not up for them or us. Night of the Unmarked is still ongoing and S2 just started so the first artist prolly got their hands full yk. nothing is weird with other artists pick this up as it’s not uncommon. like PASSION and Passion: RAGA are done by different artists as well even when they’re in the same universe, done by the same author as well so it’s not a problem at all as long as the art style is decent enough.
Omega complex is short story artist completed fast and started after they completed omega complex then work on alpha trauma unlike those stories two , these two stories are long complicated and connected since they first started night of unmarked people might get idea how this universe is connected with previous couple. They can't wait for artist to completed it which is very long story so then start thd prequel.

So, this is a spin-off of the author's other work, Night of the Unmarked? But why the artstyle is different?? Even the appearance of the characters are different...