A developer who's active on the SWGoH Reddit board has stated that they are currently looking at how to change the Arena ladder system from the current set up.
I think in the same vein as character type synergies (e.g. Lobot with Droids), they should include squad bonuses based on a team you use, similar to how Marvel Future Fight does it.
For example if you had a team with the following characters: Old Ben Kenobi, Princess Leia, Farmboy Luke, Stormtrooper Han, and Chewbacca.
You would get a team bonus for having all 5 characters together called "A New Hope" (just an example) which grants buffs to certain stats.
Aside from adding nice acknowledgements to Star Wars lore, the team buffs might encourage players to play with a team up they like instead of just using the "Flavour of the Month OP All Stars" team.