I have regularly contacted VZW over the past few months, but finally made some headway over the past week. After sending an email earlier in the week and then seperately using our corporate contacts, I received two phone calls today saying pretty much the same thing. The "on the record" answer is that Verizon is now aware of the issue due to signficant inquiry from customers and is working on a solution which they will roll out in the next few months. "Off the record" they told me that it will be out by the end of the second quarter. I also just got the following email from customer support confirming the "off the record" statements. In addition, one of the reps will be speaking to the Windows Phone dev team at VZW early next week and will give me an update
Reference Number: XXXXXXXXX
The following has been completed:
• We received your inquiry regarding why Group Messaging features do not currently work on your new HTC Windows 8 device for mobile number, XXX-XXX-XXXX.
• We researched the issue and determined this is a known issue with a possible software update that will fix this issue by end of second quarter 2013.
• Please feel free to review our website periodically at Cell Phones - Smartphones: Cell Phone Service, Accessories - Verizon Wireless for more information.
Thank you for choosing Verizon Wireless.