what are they doing to changed ranked next season?

https://nexus.leagueoflegends.com/en-us/2018/04/dev-updates-to-ranked-for-2019/

https://nexus.leagueoflegends.com/en-us/2018/06/dev-addressing-your-feedback-on-ranked-for-2019/

https://nexus.leagueoflegends.com/en-us/2018/08/dev-position-ranks-in-2019/

https://nexus.leagueoflegends.com/en-us/2018/09/dev-diary-new-tiers-placements-in-ranked-2019/

https://www.youtube.com/watch?v=Jxt2Z4hEjwE

TL;DR:

1 - Two new tiers: Iron and Grand Master. 2 - 4 divisons per tier (same number of divisions overall). 3 - Queing for different roles will not impact your main role as much as it does now. 4 - "Jack-of-all-trades" will climb just as consistently as "specialized" players. 5 - More rewards for queing up with different roles. 6 - New placements. You'll have a provisional rank after your first game, but only you'll be able to see it. You'll climb faster while on provisional games. 7 - Ranked will be divided in three splits throughout the season. Your rank won't reset in between splits and you'll get more rewards for climbing in all of them.