The simple answer is we missed those 2 items on that info page when converting the website for the new releases.
While the previous Team Workspace solution offered both -- the whiteboard through us and the screen share through Appear.in -- when we converted to our own audio and video conferencing and made it internal to SmarterMail we looked to offer both. However, development complexity came into play. The whiteboard feature was very limited in 16.x -- in our estimation it wasn't terribly useful for a number of users. It offered simple features, but not the things we felt were necessary to make it usable for a wider number of people, such as the ability to upload documents or images for collaboration and editing. Those things are more complex, and then you run into issues like "how much should you be able to edit?" -- is it true collaboration or simply markup? As for screen sharing, that's even more complex and requires a lot of planning. Appear.in obviously realized this as they've changed their own business model a few times since we initially released SmarterMail 16.x. Both solutions can cause issues with impacting server resources, increase bandwidth consumption and much more. As it is, we felt it was better to hold off adding these features in for the actual release back in December.
The nice thing about our new release process, however, is we'll be able to add in new features faster. Screen sharing is something we use quite a bit internally as it is, and we can see the need for it moving forward. We just want to make sure we offer up something that is designed and developed to be feature-rich but not terribly taxing for a mail server as mail servers, by their very nature, can be taxing on a server.