WordPress 5.6 was the final major release of 2020 which came out on 8th December 2020. I just want to highlight a couple of items that are worth being aware of now, and being prompted to remember for the future.
WordPress auto updates by default
In I think it was WordPress 5.5 a feature was introduced that allowed you to set plugins and themes to auto update from within WordPress. This was great from a maintenance point of view for some things. But, from WordPress 5.6 If you start with a fresh install of WordPress 5.6 onwards it will by default set WordPress to auto update, not just minor versions like happened in the past, but major versions also.
Depending on the website I think this is definitely a little dangerous. WordPress is generally pretty good with their releases but WordPress 5.5 caused lots of people major problems with the removal of the jQuery Migrate script which caused lots of sites using plugins that were dependent on older versions of jQuery to break.
Updating jQuery
WordPress has been using an outdated version of jQuery for a long time, and are trying to fix this with the latest releases of WordPress. Ie WordPress 5.5 tried to remove the jQuery Migrate 1.x script, then WordPress 5.6 has updated to the latest jQuery, jQueryUI and jQuery Migrate scripts, and then in WordPress 5.7 they intend to remove the jQuery Migrate script altogether. This makes jQuery compatibility a big thing with plugins, and not all developers are going to keep up the the changes. Obviously, the most prominent ones and most popular ones will, but I wouldn’t rely on developers.
PHP8
WordPress 5.6 is also designed to be compatible with the recently released PHP8. From what I have read I don’t expect that there will be much up take of PHP8 for quite a while, and if you are starting out and are able to start with PHP8 and new plugins that work with it then great, that places you in a great position for the future.
Application Passwords
WordPress 5.6 has added something called Application Passwords which is designed to go hand in hand with the WordPress REST API. It is meant to make things more secure though it has a bit of an issue. For the best explanation of this I suggest you read the Wordfence article WordPress 5.6 Introduces a New Risk to You Site: What to Do.
Conclusion
Like with most major releases of WordPress, for now I am going to wait it out a while before updating, unless there is a good reason to do so. Or, unless the website has nothing to lose by doing so. There is always a plugin that you can install to rollback the version of WordPress should things fall apart like it did for some with WordPress 5.5.