Not sure you're catching on...
A player wins the PVP mosh pit and gets crowned "emperor".
What will happen in the next big PVP moshpit?
Another player wins and gets crowned "Emperor".
A gameplay mechanic and a lore aspect converge. It's not called an Interregnum for nothing.
And considering the next two recorded names for Emperor were Cuhlecain, the "Emperor Zero" (as in Zeroth emperor of the Third Tamrielic Empire), and then the legendary Tiber Septim, first emperor to truly unite all of Tamriel under his banner, I think it's safe to say that especially Tiber has no jealousy towards all the nameless emperors that came before him during the Interregnum.
Nords? He wows you guys with his Thu'um (or was it Wulfharth's pretending to be Tiber?)
Bretons? You will be the first Tiber will roflstomp at the Battle of Sancre Tor.
Dark elves? You give up without a fight because your Gods lost access to their god battery.
Argonians? Not even your swamp can stop his legion's inexorable march.
Redguards? Not even the Warrior Wave can resist him. Cyrus's little uprising brought them to the table, but he still marched all over your land.
High elves? You get the worst of his onslaught when he sics a giant stompy dwemer robot imbued with great mythic power all over your armies because you were too stubborn and WHARRGARBL NO HUMAN RULERZ to surrender.
So count your days, Dominion/Pact/Covenant because y'all gonna get Tiber'd at the end of the Second Era.