The Four Lords and the implications (spoilers)

[Hinoto-no-Ryuji]

Is this Tenzen the FFXI Tenzen? He looks VERY similar, armor and hair. Also, Senri mentions he has a Pheonix blade, which is the weapon Tenzen in FFXI has (it contains the literal embodiment of Pheonix, which is a "Primal" in FFXI. It could be another homage like Krile and Ramza though, but then again, Iroha visited Eorzea too and the name of the orchestration roll given by the Auspices quest was "Iroha"...

He's Tenzen, in the sense that the Tenzen of Hydaelyn is clearly very similar in appearance to the Tenzen of XI, but unless outright and unambiguously stated, homage characters are never literally the same as their original versions.

As for Iroha, she's a a special case, because she showed up during an event (the only exception to the above rule outside the Omega raids).