You mean introducing the sea and everything that comes with that?
I´ve seen it mentioned that the sea might (big emphasis on might) be considered for a potential expansion. So don´t get your hopes up (´cause it will take at least a year before expansions become relevant), but it´s not completely off the table either.
Javelins were originally meant for Orcs, but they didn´t suit their combat style. Goblins, however, do use ranged weapons and are a part of the Greenskin faction.
A deployment phase will likely get added, unless you get ambushed.
Fighting in a village will get added, but as far as I know no sieges.
Probably no horses either