I agree that this game is in dire need of a test realm, though I think with all the hype and speculation that this game is built on, it would cause content to come out at a slower pace, with a lot less hype surrounding content, which is the most likely reason why we don't have this.
Having said that, I struggle to believe that you can't think of any feature of the game that has been built on player feedback. Hell, the devs removed the greed only system from 24 man immediately due to negative feedback. Off the top of my head heres what I can think of:
- Changes to finale story dungeon in HW and SB based on negative feedback for castrum and praetorium.
- Difficulty adjustments to 24man raids based on feedback for void ark.
- Implementation of NM raids because people complained they couldn't do them
- Implementation of Ultimate raids because people complained that raids were getting easier.
- Implementation of BLU (yes, that was based on the sheer popularity of the job) and Viera based on community request
- Many many quality of life changes are based on popular threads on the forums.
- And my personal favourite - Male bunny outfits.
And there's so much more, thats just off the top of my head without thinking.
Heres why: When you say something as vague as that to a mass audience, assumptions get made. Yoshi P learned his lesson about 6 years ago, when he said famous quotes like "Housing will always be FC only", "We will never create a demolition timer", "Cash shop will only be for old content", "We are planning to add a system where FCs can summon primals", and the list goes on. Essentially, keeping quiet until they have definitive news is the best course of action, because people get bitter when their interpretation doesn't become a reality.
I realize that doesn't entirely answer your question, so I will give you the scenario where he says what you quoted and it translates to "We are working to evolve BLU into something that is more akin to what players want". Even if all he meant was "we hear your feedback", what players see is "BLU becoming mainline job confirmed". That's a dangerous and reckless thing for a developer to do, especially when they have no scheduled roadmap for implementing the extensive feedback received at present.