A lot of the rules, particularly movement and line of sight will be different as Tactics plays on a grid, but warfare doesn't.
Hopefully the combat rules will stay the same.
#edit# - Having looked at the glossary on the FFG website, it looks like the combat rules and the Dust dice are indeed the same between Tactics and Warfare. The activation stage is more or less the same (2 actions per unit which can be move, shoot or something else), but they have added a reaction option if enemy units approach to close or open fire on you.
And if you want to get a head start on a faction for Dust Tactics/Warfare, Amazon Japan sell the starter set at a
reasonable price. (Its actually cheaper than Maelstrom in the UK)
Painted Minis in 2014: 510, in 2015: 300, in 2016 :369, in 2019: 417, in 2020: 450