As of build 7.3.0-alpha0-81-g99853e7 (which corresponds to git hash 99853e7a9c71d793b5b3c5028e322bf0215d2697), running db.serverStatus() against an embedded router returns the hostname/port of the actual primary/secondary process, and NOT the router. Example of running db.serverStatus() against an embedded router running on port 44000:

[direct: mongos] test> db.serverStatus()
{
  host: 'M-QKVDT236TR:44001',
  version: '7.3.0-alpha0-81-g99853e7',
  process: 'mongod', 
...

On the contrary, this is the output of db.serverStatus() running on a standard mongos process:

[direct: mongos] test> db.serverStatus()
{
  host: 'M-QKVDT236TR:54000',
  version: '7.2.0',
  process: 'mongos',
... 

This discrepancy should be fixed such that running db.serverStatus() against an embedded router returns the correct port to maintain parity with the standard router.