I see what you are saying, but its not quite making your point. If they were talking about increasingDecreasing a damage on an ability, lowering a cooldown, or introducing a new mechanic to the class then I would consider that balancing. All they did was make heat management easy. That really doesn't affect class balance much...it's more like a bug fix.
Now I don't claim to know exactly how Bioware determins how to balance classes, but it doesn't matter because you can never reach balance when you are using subjective factors. If they did that then class balance would become simply the devs opinion on how strong each class should be in any given area. This obviously would be a terrible way to balance classes since everyone is bias towards their personal experience in WZs and the classes they play.
I will respectfully disagree on this point as well. Numbers can help with balancing things like the damage an ability can do or even how much damage a player takes within a warzone. This type of data can be collected and investigated to determine if an ability needs to be tweaked or a DCD may need to be given to a class taking a lot of damage (why mara/sent ended up with so many). It cannot, however, take utility into account or the ability to shut down classes through tactics or the ability to control the battlefield with CC and that is why subjectivity must be used. There is no damage meter on how effective sorc CC abilities are or how effective classes become when used together (currently 3-4 smash specs on one team). Does the fact that Rage Juggs have push which resets leap, debuff to armor, lower CD on biggest rage building attack and taunts/guard enough to justify not having CoP, UR, and Force Camo? I think they could use a little more survivability compared to their mara counterparts, but that is where subjectivity comes in.
This is where the theorycrafting and debating side of class balance comes in and why everyone feels their class is balanced while another one is OP. Most people look at mara/sent and see the damage they can do and how effective they are 1v1, but never step back to notice that leap can't be used on command and needs to be saved for AFTER the fight starts, not to initiate battle. People underestimate the capabilities of a 4 second hard stun that allows them to get in multiple attacks while their opponent can do nothing.
I won't claim to know everything about every class and I certainly won't claim that every class is on equal footing at this time, but there is a widely held belief that mara/sent needs to be nerfed because of what it can do without anyone looking at what it can't do or how broken it would be with many of the changes offered. I was always an advocate for bringing mara/sent back in line, but have found that I have the tools to combat them now that I know what they are capable of and they truly aren't as strong as many believe.