It looks like some people in the thread below have figured it out — we actually have this. You can start a chat both ways; the system will automatically recognize if this person is on Skype for Business or on Teams.
Thanks and let me know if you have any questions.
An error occurred while saving the commentCindy commented
Yep, I've got this issue too. Even when I know the person is online in Skype it won't send or if it does send they do not receive it.
Thanks for the feedback.
We are considering a number of ways to better integrate experiences across Teams, Outlook, and other apps. However, we don’t have any specifics to share on this request.
The team continues to make progress on this. We will share more details as we have them.
We are working on the release of the Tasks application in Microsoft Teams that will aggregate data from Microsoft To-Do, Planner and Outlook with more capabilities on the way. You can see Planner data in Kanban views today, and the Tasks app will continue to support that view. In January we announced task publishing which will release with the new app. Get an overview at https://youtu.be/rTATVGroEsQ.