All Dragonrend do is forcing dragon to land by forcing the concept of mortality to them that makes them unable to fly. It's even said in the shout description.
Dovahkii: "The next world will have to take care of itself."
Paarthurnax: "Paaz. A fair answer. Ro fus, maybe you only balance the forces that work to quicken the end of this world. Even we who ride the currents of Time cannot see past Time's end, Wuldsetiid los tahrodiis. Those who try to hasten the end, may delay it. Those who work to delay the end, may bring it closer."
Paarthunax, who is specially attuned to the flow of time (and may even be able to travel it, depending on how you interpret that statement) cannot see past Alduin destroying the world and time
The idea that Alduin is weakened in Skyrim was created when the fandom tried to make sense how did Alduin became so weak in the game while in his Seven Fights of Aldudagga he's so strong. There's no conversation that implied Alduin is weakened. In fact, it's the complete opposite, MK even stated that Akatosh sent the Dovahkiin because Akatosh didn't want the current kalpa to end, indicating that Alduin have full capabillity to destroy the current kalpa at the time of Skyrim.
"Don't forget that gods can be shaped by the mythopoeic forces of the mantlers-- so Tosh Raka could be an Akaviri avatar of Akatosh with grudge against his mirror-brother in Cyrodiil. Just like Akatosh-as-we-usually-know-him could time-scheme against his mirror-brother of the Nords, Alduin, to keep the present kalpa-- perhaps his favorite-- from being eaten."
Notice all the clouds. - Michael Kirkbride
"When you consider a place like Tamriel, sometimes it's best to take titles literally. Alduin is the World-Eater. It's not going to be "the end of all *life* as we know it, "leaving a barren wasteland of Earthbone dirt... it's going to be the whole of Nirn inside his mighty gullet."
"None shall survive" has been a calling card for awhile, but that was only a hint to the more extensive "Nothing will survive."
"Unless, of course, there's a loophole. Say, something like the someone called the Dovakhiin happening to show up..."born under uncertain stars to uncertain parents." (An aside for extra credit: what in the Aurbis makes the Prisoner such a powerful mythic figure?)"
- Michael Krikbride
Basically, there's no "Denying his role as World-Eater" Alduin, that version is just fanmade, will always be fanmade unless there's in-game conversation about it. There's only "Seven Fights of Aldudagga" Alduin (which is non-canon) and Skyrim Alduin.
By the way, as far as i can remember ,eating a kalpa is the same as resetting the entirety of Aurbis, which also include the entirety of Oblivion. And iirc, there's an infinite realm of Oblivion with infinite possibilities, isn't that 2-A feat?