SQL Server 2016 SQL Agent Token Not Working
Okay, I'm now thinking this is something with Windows Server 2016 as this is the first SQL Server 2016 install I've done on Windows Server 2016.

On my Windows Server 2012 R2 (Standard) machine with SQL Server 2016, this works in a SQL Agent CmdExec job step:

sqlcmd -E -S $(ESCAPE_SQUOTE(SRVR)) -d master -Q "EXECUTE MyStoredProc etc..."


But on my new Windows Server 2016 (Standard) with SQL Server 2016, the above does not work.  I have to do either:

C:\Windows\System32\cmd.exe -c sqlcmd -E -S $(ESCAPE_SQUOTE(SRVR)) -d master -Q "EXECUTE MyStoredProc etc..."


Or this works as well:

sqlcmd -E -S $(ESCAPE_SQUOTE(SRVR)) -d master -Q "EXECUTE MyStoredProc etc..." 
GO


The cmd.exe -c argument (I was unfamiliar with) is a batch terminator; from Microsoft docs:


  -c batch_terminator
  
  Specifies the batch terminator. By default, commands are terminated
  and sent to SQL Server by typing the word "GO" on a line by itself.
  When you reset the batch terminator, do not use Transact-SQL reserved
  keywords or characters that have special meaning to the operating
  system, even if they are preceded by a backslash.


I don't know why the batch terminator is necessary in this situation...




  The GO Command and the Semicolon Terminator
  
  The GO Command
  
  “GO” is a batch terminator. Technically speaking, the GO command is
  not even a part of the Transact-SQL language. It is really a command
  used by the SQLCMD, OSQL and ISQL utilities that can also be used
  within Query Analyzer and the Query Editor window.
  
  NOTE: A batch should not be confused with a script. A batch is a set of T-SQL statements that are submitted for execution as a group. A
  script is simply a file containing set of T-SQL statements. One script
  can contain many batches.