It seems the intention is more about setting a higher bar for harassment against protected classes, rather than setting a lower bar for harassment otherwise
You're assuming good intentions on the part of the authors, but the impact is people will take away that harassment of those outside a protected class is OK. The intentions don't really matter here :-)
[CoC authors] should speak and act with good intentions, but understand that intent and impact are not equivalent.
If it's setting the bars at different levels then this seems to be a distinction without a difference (other than I guess indicating which direction the average bar height is moving?)