[Bob Cole]"Given the regulatory changes in the U.S., which frequency ranges are more likely to stay safe for wireless recording?
470-516 or 516-558?"
Both choices are "safe". I do not know of any FCC plans to auction off the 500-600 MHz band. Doesn't mean there aren't any, just that I personally don't know about them. IIRC below 600 MHz is less useful to cell phone communication, so this part of the spectrum may not get sold, or at least not too soon. There's always hope.
The 600-700 MHz band has been sold off and the apparatus is grinding away to move all the TV broadcast stations that were affected by the sale. But it's going to take years (39 months from 13-apr-2017 actually) to complete the transition. This is sometimes referred to as the "great repacking" because it's causing many (most?) broadcast stations to move even if they were already below 600 MHz (UHF 37? IDR) due to how the stations interfere with one another. It is a serious mess, and a royal PITA for those stations that went through this less than 10 years ago when we transitioned from analog to digital in 2009. This more-or-less overlapped with the sale of the 700-800 MHz band which was sold off just before the digital transition, so at least the new digital broadcasts antennas in 2009 were not in the 700 MHz block.
More than you wanted to know, no doubt, but there it is.
All the wireless systems will be from 470MHz to 608MHz with a small opening at 940Mhz with power restrictions to 50mw output The newest ones will be wide band meaning no specific blocks. Much like your FM radio in your car, you can tune to any frequency from 88-108. While the 470-608 will be the legal frequencies that does not in any guarantee clear transmissions in any given location.