I know this is already answered but....
There are other steel types and other rock types that are superior to Bastiodon. But if you really want to use it, yes I say that you should take off Magic Coat. It requires the most precise reading, and then it’s still hard to pull off. I would actually replace Magic Coat with Rock Slide, as it is much more reliable than Metal Burst. Even if Metal Burst will do more damage, Pokemon don’t always try to attack you. Rock Slide is also STAB. It also has decent power, allowing it to hit for.... well..... decent damage (though Bastiodon’s attack is garbage so... maybe not).
So that is why I would use Rock Slide over Magic Coat/Metal Burst.
Hope this helps! :)