I have verified the issue regarding GMT -7 Arizona being replaced with the GMT -7 US Mountain Standard timezone, and I will pass this information onto R&D for review.
Regarding the other issue, if you want to gather the most recent system time and your timezone has been updated since you started LabVIEW, you can always use a Windows API call (provided you are on a Windows OS, of course). Look into calling kernel32.dll in a Call Library Node from LabVIEW and using functions such as GetLocalTime, GetSystemTime, or GetTimeZoneInformation.
I've attached an example that gets the local time continuously. Test it out. You can change timezones and times from the Windows Taskbar and it will update automatically. The data obtained is a struct with various numeric values such as month, minute, second, etc. I formatted this data into a LabVIEW timestamp format, but you can do with it what you please.
Hope this helps!
Jarrod S.
National Instruments