WHM/cPanel have been their usual slow (cautious) approach have made MariaDB the future replacing MySQL.
We upgraded this morning. MariaDB is faster and has a smaller memory foot print.
Initially I'm seeing up to ~20% surprisingly faster database; but this won't make a huge difference to your site experience as the database component of any page hit is only 10-15%.
I.e. maybe 2% of the overall transaction.
Why upgrade?
MariaDB is faster
MariaDB has some better features in regards being resilient to crashes
MariaDB has less bugs/issues than MySQL
Very large sites (eg. Wikipedia) have changed to MariaDB
MariaDB also has more than 10,000,000 users now (lots of people with experience and bugs reports etc.)
It is now the default database on some major Linux distributions (again well supported)
It is plug compatible with MySQL - it is easy for us to change
MariaDB is the future and we are protected from the whims of Oracle who now control MySQL
The MariaDB core team is ex MySQL because the did not like Oracle's approach