I'm aware of those quotes, I just don't agree with your RAW conclusion. Call it a debated topic, but you can't prove it is extraplanar because it doesn't say the creature gets extraplanar tag. It only says it has Magical Beast. If what you suggest was RAW, that would need to be specified and it isn't.
You are screwed...
I think there is a class that grants Ex wings.... Not sure which. Let me think. It would be 10th level capstone ability tho.
I know Dragon Disciple grants wings.
9th level bonus
'At 9th level, a dragon disciple grows a set of draconic wings. He may now fly at a speed equal to his normal land speed, with average maneuverability.'
Besides that, I wouldn't know.