In addition to PostgreSQL 12.1 the community also released versions 11.6, 10.11, 9.6.16, 9.5.20, and 9.4.25. As a rule of thumb, for production workloads, I avoid any new major version until a .1 version has been released. I have already tested PostgreSQL 12 in an evaluation environment and have not run into any issue. It should also be noted that PostgreSQL 9.4 will stop receiving fixes on February 13, 2020. Currently, I am running in production PostgreSQL 9.6 to 11 so we are not close to EOL, but I am still motivated to upgrade my PostgreSQL instances.
All PostgreSQL minor version releases are cumulative and there is no need to dump and reload your database or use pg_upgrade in order to apply these releases. Generally, you will simply need to shutdown PostgreSQL and update its binaries. While there may be legitimate reasons for not performing a major version upgrade, there is rarely a reason not to apply a minor version upgrade.