BUG #16756: about pg13.0 new feature--“Remove --adduser and --no-adduser from createuser”

The following bug has been logged on the website:

Bug reference: 16756
Logged by: yanliang lei
Email address: leiyanliang@highgo.com
PostgreSQL version: 13.0
Operating system: CentOS7.6
Description:

in the https://www.postgresql.org/docs/release/13.0/ ，there is following
descrption:
Remove --adduser and --no-adduser from createuser (Alexander Lakhin)

but in the pg12.1 version's createuser --help output，there is no --adduser
or --no-adduser ，I want to know why？

[pg121@iZm5ehqfjhnsbtxrzrnh2zZ ~]$ createuser --help
createuser creates a new PostgreSQL role.

Usage:
createuser [OPTION]... [ROLENAME]

Options:
-c, --connection-limit=N connection limit for role (default: no limit)
-d, --createdb role can create new databases
-D, --no-createdb role cannot create databases (default)
-e, --echo show the commands being sent to the server
-g, --role=ROLE new role will be a member of this role
-i, --inherit role inherits privileges of roles it is a
member of (default)
-I, --no-inherit role does not inherit privileges
-l, --login role can login (default)
-L, --no-login role cannot login
-P, --pwprompt assign a password to new role
-r, --createrole role can create new roles
-R, --no-createrole role cannot create roles (default)
-s, --superuser role will be superuser
-S, --no-superuser role will not be superuser (default)
-V, --version output version information, then exit
--interactive prompt for missing role name and attributes
rather
than using defaults
--replication role can initiate replication
--no-replication role cannot initiate replication
-?, --help show this help, then exit

Connection options:
-h, --host=HOSTNAME database server host or socket directory
-p, --port=PORT database server port
-U, --username=USERNAME user name to connect as (not the one to
create)
-w, --no-password never prompt for password
-W, --password force password prompt

Report bugs to <pgsql-bugs@lists.postgresql.org>.
[pg121@iZm5ehqfjhnsbtxrzrnh2zZ ~]$