Acc to the Shulchan Aruch Harav there are two mitzvos; limud torah and yidiass hatorah. Even if there is no limud here, the listening probably generates yidiass hatorah. For non-chabad chassidim I don’t think this requirement of shomeah kioneh is followed so much or else this extremely-relevant-to-daily-living- din would be very famous and people would announce before shiurim to michaven lotzes.
(I don’t know why the requirement of mitzvos tzrichos kavanah doesn’t apply to talmud torah especially since it is a mitzvah dioraysah. Why doesn’t everyone have to first think that I am now fulfilling the mitzvah…. before every torah related discussion. It may be because the source for MTK from aseh lishem poalam does not apply to talmud torah as the Nefesh Hachaim discusses.