This launch enables TCP port randomization on versions of Windows (2020 H1 or later) where we do not expect to see issues with re-use of prior ports occurring too fast (causing rejection due to timeouts on port re-use). The rapid port re-use issue arises from the Birthday problem, where the probability of randomly re-picking a port already seen rapidly converges with 100% for each new port chosen when compared to port re-use in a sequential model.
When port randomization is disabled (the default), sites are able to count the amount of connections opened by other tabs if they check the TCP port used for new connections before and after opening another window. This knowledge can be used to glean information about other sites like whether they are logged in or not.