Not in my experience. I've re-finished the frets on all my "store bought" guitars the same way and I've never had a problem. The steel wool takes the edges off the flat tops anyway. I'm not sure why you think it would create buzz.
What you have described is how pro luthiers would do it, but you'd need a much more expensive crowning file. Plus, unless you know exactly what you are doing, there's a real risk of undoing the fret levelling.