Are you actually getting a 5G service, or is this preparation for it, or is there a service provider called 5G?
If it is a 5G service, bandwidth should not be an issue. It sounds like they are just streamlining/pruning out less profitable services. Then using 5G as an excuse.
From the look of the cuts listed in the original post, a lot of the cuts are the HD versions but the standard (lower quality picture) channel remains. They may also be cutting channels that have a lower audience because it is not attracting advertising. This cuts choice, especially for people who do not have mainstream interest. This is a good reason for public service broadcasting like the Beeb. I know we all like to complain about the licence fees, and some people see some of the stuff on BBC 3/4/5 as dross, but one mans dross is another mans enjoyment. If you don't like the stuff on BBC3 you are probably not the target audience. The target audience may be small, but then we are back to public service broadcasters providing non mainstream content (alternative viewing).