Well I think I've found my class now, was hoping for a more knightly class but I'm confident the monk will be engaging to play as.
I hope this class will be all about channeled attacks through their staff or whatever other weapon(s) they use, and not have any hand-to-hand combat skills tbh, fighting against demons like that just never seemed fitting to me.
As for lore, I'm betting the monk will be a disciple of Zakarum (think holy bolt, its a staple of this series) like the paladin, but studying in seclusion somewhere instead, and will be more spiritually inept (kind of a given really). My guess is that he/she will be from somewhere near or in that mountain region near Ureh.
I hope they don't go cheese though and just spin the lore off from that monk in the old D1 xpac.