The Jutsu was only possible thanks to Cooperation Ninjutsu which we know is far greater than the sum of both parts. Jiraiya specifically states within the arc that Boruto and Naruto have a bond that goes beyond
just synchronization. To be specific, the only reason Jiraiya decided to train Naruto and Boruto to learn Cooperation Ninjutsu, is because Naruto's psyche reacted to Boruto grabbing onto him while Naruto was influenced by Kurama. Jiraiya surmised from this interaction that they are highly, highly, compatible and that their chakra signatures are incredibly similar. Jiraiya even states that he has no idea what kind of Ninjutsu they'll end up developing because their circumstance is far from the norm, and different from any normal Cooperation Ninjutsu he's seen.
Against Transformed Urashiki, Naruto goes on a rage and spams ranged Jutsu in his 1 Tailed form,
but Boruto is able to once again, tap into Boruto's psyche and connect to Naruto on a deeper level, creating a massive Rasengan which was thanks to the emotional, physical and spiritual/mental bond that they share that is BEYOND the scope of regular Cooperation Jutsu training (which includes similar chakra nature, flow and power).
So yes, this feat falls precisely under the definition of empowerment that exists on the wiki. It being an outlier feat is a poor argument because the circumstances of the Jutsu
IS an outlier within the verse.