The problem is the 2.4GHz frequencies, which are not true radio mic frequencies. I doubt that, even now, they would would perform reliably given the growth in use of WiFi equipment.

Channel 38 is the official dedicated radio mic range which is not changing in the forseeable future. Channel 69 was sold for 4G, and many channel 69 radio systems are able to use the deregulated part of channel 70 (all my Sennheisers, for example), and there are no plans for that to change. People who continued using their channel 69 equipment are now finding they are subject to a lot of clicking and popping from mobile phones!

Here is some relevant information, and 2.4 information...