Why do Raid Buffs even exist?

[Razhius]

META (Most Effective Tools Available) is a common terminology for a set of actions, equipment, strategies, builds etc. that a community agrees on to be (highly) viable if not the best to use, depending on various circumstances.

Not once have I heard that community agreeing to a common standard organically and developer intention bruteforcing it needing to be mutually exclusive to call things "meta". The commonly used terminology is the acronym named above, so I'm not sure what your intent is here. It is a 2min meta, whether you like the terminology or not.

Some sources to read up about it:
[DOT Esports] What is “the meta” and how does it affect gaming?
[Plarium] Meta in Gaming: What Does it All Mean?
[ggn00b] What Does “Meta” Mean In Competitive Gaming?
[GINX.tv] The Meta or Metagaming, explained in less than 3 minutes

They may not all be 100% accurate, but not once am I reading "must be mutually exclusive with devs intention" in any meaning.

If the ffxiv players come up with a way to effectively make the 2min rotation burst DEV DESIGN any better, or ways to make it effective without lining everything up in this rigid design, guess what, that is a Meta that emerges from SE's battle design.

You are arguing semantics. All I'm saying is that at the moment all battles (at least at ex/savage tier) are DESIGNED to work around the 2 min burst mechanic they introduced to almost all classes, and probably will slowly introduce to the rest in the coming patches.

If a team does p8s without lining anything up and still make it, that would be finding a meta that works outside their battle design decisions. (Thisd wont happen though, because battles are so choreographed and finely tuned to be done in just 1 way that diverging from SE's "Meta" is impossible).

Edit: yes META would stand for Most Effective Tool Available...

But in this case we have "The Only Tool Given By SE".