Can we use wildcard characters on the PostgreSQL hba_conf file for database names?
According to the documentation for The pg_hba.conf File, you can have:

database
Specifies which database name(s) this record matches. The value all specifies that it matches all databases. The value sameuser specifies that the record matches if the requested database has the same name as the requested user. The value samerole specifies that the requested user must be a member of the role with the same name as the requested database. (samegroup is an obsolete but still accepted spelling of samerole.) Superusers are not considered to be members of a role for the purposes of samerole unless they are explicitly members of the role, directly or indirectly, and not just by virtue of being a superuser. The value replication specifies that the record matches if a replication connection is requested (note that replication connections do not specify any particular database). Otherwise, this is the name of a specific PostgreSQL database. Multiple database names can be supplied by separating them with commas. A separate file containing database names can be specified by preceding the file name with @.

That is, wildcards are not possible, although you have all the following alternatives:

The value all, which is actually working as a wildcard matching &quot;all databases&quot;.
The value sameuser, which is a database with the same name as the user that connects to the database.
The value samerole
The value replication
Multiple database names, separated by commas.
@FileName, specifying a file which contains the names of the databases

In your specific case, you could use:

fcca, fccb, fccd, ...
@fcc_names.txt

(and have fcc_names.txt filled in with all fcc* database names)