Something like that is rumored to happen based off the fact that a 1H mace model for one of the priest’s healing staves was found in the game files of 11.2.
My guess is we’re going to get alternative “types” for the weapons.
Example: Priest will get a 1H mace version of their staff, or a staff version of the dagger so they can use them more easily in tmog. DK might get a 1H version of Apocalypse for tmog, or a 2H version of frostmourne at home.