Not in my experience.
Under lvl 55 WZ are at the moment much more imbalanced than they were before.
With the exception of the dreaded lvl 49 pimped twinks, pre lvl 50 WZ before the patch were almost perfectly balanced anyway with everyones hp between around 11-13k HP. When 2.0 went live, you could see people between 18k and 33k HP in the lvl 30-54 WZ. Two hotfixes later, there still is a potential gap of 6-7k HP (23k to around 29K).
LVL 55 WZ zones now see around 25kHP to 33K HP (we are not even discussing the mess when 2.0 went live). Expertise varies largely depending on the question if people got the memo of removing the expertise crystals from their old PVP gear.
PVP NOW is a mess.
And do not get me wrong: My juggernaut has read all the memos and now sits happily at the top of the food chain with 32K HP at lvl 55 and about 1,8K expertise (mostly remodded EWH + Conquerer+Partisan). I just would never dare to claim that it is more balanced now.
Not to mention there are certain things that can be done to create 45k smash monkeys in the 55 bracket if you're willing to spend some money, creating quite the huge gap between people. Anybody who says that bolster doesn't create an unbalanced system are only trying to fool themselves. It's hard to understand why people are in such support of a broken system. If BW can't figure out such advanced programming and algorithms, do the easy thing and either create free GEAR for their intended stats they want for introductory play, or make everybody start with the same stats/expertise for their specific role and if that number isn't met, that's what you are automatically bolstered to. Whatever they're doing now is obviously just not working and each 'fix' they try seems to just screw the pooch even more.