The Drop isn't the only thing that is moving; so is PHP. If you have a Drupal 6 site you are most likely running PHP 5.3 or older, versions that stopped being supported in 2014 or prior. Now that PHP 5.5 has moved out of active support, some hosts, such as Acquia, are dropping support for anything older and sites will be forced to upgrade, ready or not. The good news is that Drupal 6 can be made to work with PHP 5.6, which is actively supported.