The only time fixed port numbers are inconvenient is when they conflict, but otherwise they're much easier to work with.
Of course, one day the technical inferiority finally shows itself (e.g., the ports do conflict), and then people start to heroically overcome the obstacles they've created for themselves, showing outstanding feats of ingenuity. Just google "port allocator"! Every company inevitably writes their own home-grown one because everyone's deployment/integration pipeline is unique.
It’s likely that the port will be available indefinitely.