I would sooner see certain units as being iconic of certain Eras, for various reasons.
For example: the Timber Wolf is arguably the iconic Clan 'Mech of the era of Operation REVIVAL, to the point of it being used to mark the Clan Invasion Era by CGL themselves.
Yet might the Savage Wolf be considered a more representative Clan 'Mech of the Dark Age era? Not just in terms of being one of the "new" designs bequeathed to the setting by MechWarrior: Dark Age/Age of Destruction, but also in-universe as the chosen 'Mech chassis of both Alaric Ward and of Anastasia Kerensky. Indeed, with the latter's Savage Wolf being used on the front cover of the IlClan sourcebook (and the former's on the back cover), that design's prominence in the universe does not appear to be going away any time soon...
But then, one could also argue that the Ares is an icon of the Dark Age, from an Inner Sphere perspective. There are few "new" MW:DA/AoD designs which, for good or ill, have been as symbolic of this era. Yet while the Republic it was originally built for no longer exists, it too is now beginning to proliferate across the setting, as more factions gain access to these superheavy tripods in the ilClan Era.
Although, I might also wonder what designs, be it Clan or IS, would be emblematic of Catalyst Game Labs' stewardship of these new eras. I think of new Clan designs like the Hammerhead, which is already being used as one of the 'Mechs featured on the cover art for BattleTech Universe. If the Timber Wolf and other TRO:3050 'Mechs spoke to the Clans of the REVIVAL era, the Hammerhead symbolizes the degree by which the Clans known to exist as of the 3150s have adapted from over a century of life in the Inner Sphere and known Periphery.