How is this service registering with listener when invalid LOCAL_LISTENER is used?

I have a single instance 19c CDB with 2 PDBS, I am also running Grid Infrastructure (Oracle Restart) for ASM.

The database has LOCAL_LISTENER set to LISTENER_MYDB which is a non existent listener, and a non-existent entry in tnsname.ora

There is a listener (default name LISTENER) running on a non-default port 1641

I have create a service with srvctl for the PDB called MYDB_SRV

It shows up under lsnrctl status

[oracle@ +ASM ~]$ lsnrctl status

LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 29-MAY-2023 13:04:01

Copyright (c) 1991, 2022, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=MYSERVER)(PORT=1641)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 19.0.0.0.0 - Production
Start Date                05-MAY-2023 23:49:25
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