It's annonying, but it's what we call a stutter release, where one release creates enough bugs to require another. Joomla 3.6.1 had issues with ancient versions of PHP, and had trouble with its internal email masking software. Neither of which concerns any of our clients. But just to keep things current, we've updated all our sites to Joomla 3.6.2. Just part of the process. I'll refer you to the official announcement and details.