Gbg was single handed the worst addition to the game ever added.
It took the game from reasonably balanced to a 24/7 farming cash cow. (Theres been a lot more inbalance since but that was the starting point)
That said this update only reduces (or potentially reduces) rewards indirectly and increases costs.
It does nothing to solve the main problem, which is every server now has maxed or close to maxed out guilds of players that can access the game 24/7 and fully focus on gbg, everyone else now in smaller guilds bouncing between diamond and platinum. They get a good platinum, get moved up to diamond, get kicked around/blocked for the next season or might scrape enough to have two blocked diamond rounds then go dropped back down to platinum to a decent round in platinum and then the circle begins again.
Honestly do not see the point, I could join the gbg guilds tomorrow but for what? the game shouldn't be inbalanced to the point where there's limited amount of guilds that can play gbg normally and steadily and the rest get booted around like old tin cans by them week in week out.