I don't think it's a big deal, for reasons I outlined in this thread, but remember that ETrade and any other broker will always issue the disclaimer that they do not offer specific tax advice. Same is true here, of course. I think their logic might be that since the RSU was already taxed at the highest income tax rate when it was issued (as a form of earned income/"wages"), there is no way that buying it avoids tax on an unrelated sale. For your own records, you might document your call in a dated note or email to yourself noting what they told you.
