literally the textbook definition of a tsundere
Bulbapedia is incorrect. All moves (with the exception of moves that can change type like Judgment or Weather Ball, even if they remain Normal, as well as CFZ moves) even if they were Normal-type originally, get the Normalize boost.Normalize is boosting the damage of all moves, not just non-Normal moves that are turned Normal. I thought it might be just a bug with the mouseover info, so I tested it.
These Lonely Guzzlords are Banded, have 0 Defense IVs, and 252 Attack and HP EVs. Despite Thrash dealing a bit more damage, that's just due to damage rolls. According to the calculator, the maximum a non-Normalize Thrash or Dragon Ascent can do is 507.
According to Bulbapedia, moves that are already Normal-type shouldn't receive a boost. However, because this "bug" has existed for quite some time, the Smogon Ability Dex implies that the boost happens regardless of the original move's type, and Normalize is a pretty obscure ability that probably no one but Smogon would research in-depth, there's a very real possibility that this isn't a bug and Bulbapedia is wrong.
e: here's a link to the original research on smogon: https://www.smogon.com/forums/threads/pokemon-sun-moon-battle-mechanics-research.3586701/post-7125289