It doesn't sound like the hearing coming up in your case is a 341 meeting. Instead, since the trustee had to file a motion for the hearing, it sounds like something very different, indeed. The hearing may be continued to a later date in order to accommodate the new Chapter 7 trustee. However, it just as easily may remain. I would plan on attending. You can check the court's docket at www.azb.uscourts.gov. If you have further questions, call your bankruptcy attorney or a local attorney for assistance. You should plan on being at any hearing the court schedules unless the court or your attorney informs you otherwise.
Once the order has been signed converting your Chapter 13 to a Chapter 7, any hearing by the Chapter 13 Trustee will be taken "off calander," which means that the hearing won't take place. In Nevada, obtaining this order doesn't usually take more than a couple of days.
However, converting to a Chapter 7 may not make the issue of the back tax refund go away. Rely on the advice of your own attorney, as the specific details involved in your case will determine the outcome.
Hope this perspective helps!
The right to convert your Chapter 13 case to Chapter 7 (assuming you pass the Means Test) is automatic and the order will immediately enter, so the 341 hearing in the Chapter 13 case will be vacated. Depending on the amount of the tax refund and who the Trustees are, this may cause a fight over the tax refund between the trustees.