Valid concern, but in this case it seems like the roots have been there, and likely plenty under the surface, for a while. Look up neagari. Exposed roots up top like that is totally a thing in bonsai.I’m a beginner, too, so pardon the dumb question: will it be ok with that much root mass exposed? Seems like maybe it was rushed to get to that angle.
Am I bit late repotting this one?