First things first, we need more ships. Give Nute his Capital Ship, Holdo (yuck, I know), Snoke and Supremacy in March, and maybe a few others (Malevolence comes to mind, with a group stun ultimate. I like Grievous' starfighter, but he would be a cool fleet commander too), Nihilus and the Ravager.
We need a LOT more starfighters (JKA, Luke, Dooku, Kenobi, Palpatine/RG shuttle, IG-88, Vulture droid, etc), but first and foremost THE REAL MILLENNIUM FALCON (with CLS level OPness - perhaps a dual heroes journey for OG Chewy and OG Falcon?).
If they drop a massive ships update, the variety will shake up fleet arena for at least a few months, with all the new combos to try out. And if things get stale after that, they can introduce hardware and other stuff.