I just found out this feature was removed because "teachers weren't using it" according to support. I know at my school we heavily utilized this feature for quick activities like discussing the ending to a book in ELA. It was incredibly convenient to finish reading, pose the class a question, and have everyone engaged so quickly. Obviously one could still create a collab board and do the lesson, just losing the convenience of two click launch feels really, really bad as it now takes much more forethought and setup. So if you enjoyed the quick launch feature please comment and upvote to maybe bring it back!