Thanks to Babykim on the EU forums for translating this important tidbit! Ranked will be returning – though no exact date is specified – soon, possibly alongside or shortly after patch 5.6, which leads me to believe the new season will begin in early June.
Also, we’ll be able to test it in an upcoming public test for patch 5.6, which seems to imply that the devs have indeed made changes to Ranked as many people have hoped. That’s jusy my thought, though; we’ll have to wait and see for more information.
The developer Vallter_ says:
We know that players would want to prepare their ships and captains for upcoming rank battle seasons, and therefore need to know which tiers will be eligible. The next rank battles season 4 will be held at tiers V, VI and VII. Those who are confident that they will reach rank 1 may prepare their tier X ships.
EDIT: You will be able to test the rank battles during the general test for the update 0.5.6, which will take place during the coming two weeks.