start new difficulty with same character
it would be rly cool if you can explore a harder difficulty after youve finished tactical mode. BUT! you shouldnt start new. You should play the same characters with the lvl and items from the last campagne. That requires ofc a higher max lvl, and the npcs have to be (idk maybe 30) lvl higher too.
a big pro is that there will be a bigger playerbase because everybody keeps playing much longer.
----> less empty pvp lobbys
----> less empty coop lobbys
----> more ppl who may buy some upcoming dlcs