WooCommerce 3.9 is currently in development and is set to be released early January 2020. One change of note will be the new minimum PHP requirement: PHP 7.0 – any site running on an older version will not be able to update when it becomes available.
I’m glad to see WooCommerce continuing to push the minimum version required, even though PHP 7.0 reached End of Life in January 2019. Hopefully this recent push from WooCommerce and WordPress itself has prompted many site owners to respond and update. The speed and security benefits are well worth the trouble.