I am not going to read every post in this thread. I'm not going to weigh in on who's more right than anyone else or who worded what poorly. At the end of the day you're all just users of Zenimax Online Studios' product. And that's the crux of it.
@ZOS_GinaBruno, and the rest of your team, I'm going to give you a bit of advice: Disable Lua addon support entirely. Your API is overly, unreasonably limited and when it comes down to it it's fairly obvious that your company either does not really concern themselves with Lua or the API any further than as an afterthought, or that your company is utterly clueless on how to properly manage it.
API updates must be announced in advance of upcoming patches clearly so that your addon developers (IE: those people who dedicate their free time to improving your product and garnering you additional users and accounts through their voluntary, unpaid support) can adapt to your API changes in advance and possibly even provide feedback before you cross that point of no return.
This kind of update has become standard for ZOS and ESO. 0 warning, just pull the trigger. Leave your addon authors guessing because, well, why not... they'll just figure it all out again anyway, right?
If I handled my day job as poorly as your API team does there jobs I wouldn't have my job. I've been in Information Technology for 22 years. I've been programming in one capacity or another for 28 years. I've been on good teams, bad teams, Waterfall projects, Scrum projects, Agile projects, blended cobbled together horribly managed projects, etc. Whatever excuses anyone wants to bat around for the way things are being handled, trust me... I've heard them. Whatever challenge you think you're facing, trust me... I've faced it (and for a lot more serious industries such as military & healthcare). Rest assured, none of the excuses make up for it.
So... just stop. Turn it off. Be a game with a non-customisable UI like you obviously want to be and just be done with it.
I've clocked almost two thousand hours working on addons, a website and talking to communities for this game since October 2013 pre and post launch and while I enjoy playing it I'm || close to just dumping all of my projects and walking away... mostly from the lack of "care" that I see for the subset of your community that I'm a part of.
From my experience with other online games, I've always held the notion, "What happens on the PTS, stays on the PTS". I discovered that the hard way back in the early days of WoW....I had expected someone to make the rebuttal to Wykkyd's post, saying that we have the ability to test new API changes on the PTS prior to their release..