Dragonite was 4x weak to Ice and that didn't stop him from topping Mamoswine. Type disadvantages doesn't hender a Ash Pokemon performance in battle you guys should know better.
And we have no idea when Wulfric's battle will be or what kind of fights Noibat will have been through by that point. lol
Very true, but keep in mind that Dragonite was also portrayed as being abnormally strong and resilient even for its species. Most spectators, including the main cast and supporting characters were shocked when they saw it tank those Ice-type moves. It's quite rare for Pokemon to be characterized like that (with Charizard, Dragonite, and a few others being the rare examples). Given Noibat is easily the youngest and least experienced of Ash's Pokemon, even if it is a Noivern by Wulfric, it's unlikely to show the same endurance. It might take one or two hits, but by no means will be it simply shrugging them off. And that's before taking into account that Dragonite as a species has always been portrayed as reasonably tanky, as opposed to Noivern, whose species is known more for speed and long-range attacks. Furthermore, Iris was battling Georgia's Beartic, which was reasonably powerful. But Ash will be battling Wulfric, the strongest Gym Leader in all of Kalos and a master Ice-type trainer. Presumably his Ice-types will be far more powerful than Georgia's were.