I don't know about making fun of a dialect, but it's not quite utter nonsense - "oven" sounds like "of in", so it can be interpreted to mean that it shouldn't be called oven, because when you put the food in it's cold, you only eat it when taking the food out, when it's hot.
The sentence structure is so absurdly wrong it makes me wonder if somebody was genuinely trying to make a pun and ended up with that, or if it was intentionally butchered.
Yes, but it doesn't change the fact that some people won't use it for that reason, and makes it a fair question if the new model is also "slow".