Now its merged for classic and XL, XL stages will have red label, for example on this picture is YTR (imperial forces ver, YT ver, YT ver XL, nanman ver XL)
https://x.com/s_sangokumusou/status/2064180684978029030/ (JP)
https://x.com/omega_force_EN/status/2064331683629846856/ (EN)
We can access those previously announced new stage (shu's he fei castle, wei's chibi, wu's wuzhang plains) by pressing triangle button after we unlocked it on certain conditions
Battle of Hefei Castle (shu) : what-if guan yu and zhang fei survive on fan castle, zhuge liang propose to counterattack on wei
Batttle of wuzhang plains (wu) : final battle for lu xun vs zhuge liang + sima yi
Battle of chibi (wei) : just ordinary what-if chibi for wei, what-if guo jia exist