I haven't thought through how 5G would impact our capability overall, nor do I know enough about 5G to really want to advise you on it.
If I were to make an assumption and set my own fictional narrative, I would say that 5G is going to speed up our ability to transmit data. That should not impact the propositions that I'm making. I would say that they still stand, meaning that if it's simply the speed through which data is being moved, then if you've set rules and policy for how your applications and servers interact.... These are a little bit different. They are two different beasts, and they shouldn't negatively impact one another.
If I were to think about a capability that would disrupt the future of computing overall, leaving aside microsegmentation, I think quantum computing would be the main thing I would be looking into for something that would totally alter the nature of cybersecurity. Even then, I don't think the security stacks would be totally disrupted.