i feel like shane and mark doesn't want brian back. for kian i don't know his stand. but i love nicky. he is more mature than the rest of the guys. he is open for a reunion and kinda understand brian's departure and respects it.
how will Brian will fit into the current dynamics even though he missed a lot of albums, however it would be strange if bringing BM back to WL because it's like a boyband reboot, restarting a new group or relaunching as five piece, it would be more like restarting new. Westlife are already doing fine without Brian. I'm sure that WL didn't forgive him for leaving the band in 2004. So it was BM's fault, leaving the band is a big mistake, his solo projects didn't reached into popularity.