Telecoms fag reporting for duty.
You raise an interesting question. As standard, it is the responsibility of the hosting country to define the frequencies at which mobile telecoms equipment may operate. The available frequencies are then sliced and diced, and sold off to the highest bidders.
The telecoms base stations are then configured during install to work at the determined frequencies. In theory, they should not work at any other frequencies. I believe but am not 100% certain that the h/w is configured at the site. I know for a fact that in the UK one telecoms operator was caught poaching frequencies that had been licenced to a different operator. They claimed it was a config error.
Mobile phones operate within a frequency range. They usually only connect to a base station which is operated by the provider with whom the user's contract is held. The exception is 999 calls (911) to emergency services. Any base station maybe used for such calls.
If Huawei telecoms equipment can be remotely configured to operate in frequency bands that are not licenced (i.e. above 50Ghz) then we have a serious problem. However, all of the config details that this anon have seen do not support this theory.