At least I don't think it is. When you take into context what The Speaker says in the reveal teaser ("You've carried us into a new age"), this moment in the Destiny timeline is actually the first that we the players are responsible for.
Every other moment in said timeline is broken into their own "ages":
The Golden Age– The discovery of The Traveler, the evolution and expansion of mankind.
The Dark Age– The lawless, dangerous universe as it existed after The Collapse. The Traveler's "last breath", the creation of Ghosts and what would eventually become known as Guardians.
The City Age– The emergence of The Last City, the inception of The Vanguard, the factions, the Consensus, etc.
There are obviously points of importance within each age (the fall of the Iron Lords, the Great Disaster, the battles of Six Fronts & Twilight Gap, the Reef Wars, etc.) but on the surface there have been 3 ages, and now there is a fourth, The Age Of Triumph.
An age where Guardians have grown stronger than ever, and have thwarted every threat to the City that has come. Atheon, Crota, the House Of Wolves, The Taken King, the Devil Splicers and inadvertently all of the Cabal command in our star system.
We awoke the Last Warmind. We convened with the Awoken of The Reef. We destroyed the heart of the Black Garden. We unseated the Osmium Throne. We contained a virus that would have consumed the planet, and in the process avenged our forefathers the Iron Lords, all the while becoming one ourselves.
From a lore standpoint, we have indeed "become legend", and this age is the end result of our countless, unfathomable victories. An age of revelry and celebration that (most likely) will set the stage for a massive shake-up that will reveal that even as we've done so much, the battle isn't anywhere near over yet.
That's for another time though. For now, we're in a new age…the first one forged by our own hands and not those who came before. Let's enjoy it for what it is as we embrace (or simply brace ourselves for) what's to come.