As of the 10th March 2020 WooCommerce 4.0 was released into the wild! The update sees the merging of the WooCommerce Admin plugin into WooCommerce core and updating of the Action Scheduler to version 3.1.

With your website being a live production and this being a major release that will greatly impact the functionality of your website we will not be implementing this update or the updates of other related plugins.

As can be expected with an update this big; bugs and teething problems will be present. Already the following have been reported amongst many others:

The data might not import and there is a chance the sites servers CPU might spike.
https://wordpress.org/support/topic/huge-spike-in-cpu-usage-account-executions-after-4-0-update/

Fatal error after updating.
https://wordpress.org/support/topic/fatal-error-after-woocommerce-database-update/

As is normally the case, we would advise all clients with administrator access to avoid the urge to action the update. I know a nice new shiny admin dashboard is tempting, but due to the complexities of the websites we usually build, we will undertake individual testing on clone websites to be sure everything is running smoothly before we push it live to your website (Please note: we will only be doing this for clients with an active maintenance plan).

There is currently no announced date for version 4.0.1, but we will continue to monitor the situation closely.