You're going to be pretty underwhelmed by the Intel graphics. Yes, it will run... No, it will not look great. At the minimum, I suggest looking for a dedicated graphics card.
For what it's worth, I can get default X-Plane to run on my late 2014 MacBook air with the medium to low rendering presets. I'm not a pilot, and I don't need a ton of detail when I test or investigate bug reports. I don't use much 3rd party scenery, aircraft or add ons. When I do use them, X-Plane's FPS can drop like a rock, into the single digits, which is completely un-flyable (some would argue mid-20s is unusable).
Is there a reason you really want or need a MacBook, or just a laptop in general? Here is a topic on the forum of X-Plane.org (a site that is not affiliated with Laminar Research or X-Plane itself) that goes into a lot of detail that might help you pick something. Keep in mind it is a little old now for the outlined specs, and some of the updates we've released since 2010 have increased the minimum system reqs to what you find on our site.