It's pretty clear that SSJ2 Gohan was retconned.
Vegeta knew immediately that Gohan slacked off at the Budokai yet before Gohan battled Dabura, Vegeta didn't give a resounding statement of Gohan having been rusty. Instead, he presumed that Gohan was rusty and it wasn't until Gohan fought that Vegeta had the same response as he did towards Gohan at the Budokai. Hell, Goku was completely oblivious to Gohan having slacked off and he sensed both the "Standing Ki" of Kid Gohan and the "Standing Ki" of Teen Gohan. For fuck sake, Goku has the deepest understanding of Gohan's power ever since the Frieza Saga ended. You'd think Goku would've been able to tell if Gohan was weaker or not.
Honestly though, the whole Standing Ki =/= Fighting Ki is a huge cop out. If what you're arguing is the case, then power levels would've shot up immediately when a fighter battled and that's non-existent in the manga. Regardless, both Goku and Vegeta sensed Gohan's Standing Ki at the Cell Games, so it doesn't matter either way.
