Hints why I interpret it as open ending and that he only passed out :

1) everyone else was shown fatally wounded (stabbed, shot, exploded) except for CX, the bombs also missed him. If they wanna give absolute death, they would have shown him shot multiple times and bleed out.

2) Xiao Beichen shown as alive after being presumed dead in his own drama series (If that is not hope, I don't know what is). Means also Yu army are not on their own.

3) QiXuan is there working as a nurse, it's not random.

4) one year passed and PJ still hasn't received news to confirm his death, therefore they are clinging to a real hope that he can still come back.

I do not hope for a very clear HE as I think censorship won't allow it. Warlord era must die together with the warlords to give rise to New China and CCP. But I think this is Director's way of something giving a bit spark of hope.