Over three years ago, the content pages in JX were complete redesigned (you can read more about that here:Content deep dive). And then again a few months later, the rich text editor was also upgraded/redesigned (more about that here:RTE deep dive). When we rolled out those new features, we also added the ability for customers to toggle them on and off, in order to acclimate themselves and their user base with the new functionality. In the upcoming 2019.4 release,these feature toggles are going to be removed and all customers will automatically use the new content types and the new RTE. Nothing needs to happen on your behalf, it will happen automatically during the upgrade, but you can also toggle them on yourselves today (if you haven't already) to start getting used to a newly, modernized view of the content pages. Again, let us know if you have any questions or concerns about this!