Lossless rotation of JPEG data is based on the implementation in the jpegtran utility of the Independent JPEG Group (IJG) software.
jpegtran has an option -copy all so that metadata is not lost.
Applications using the IJG code usually have the -copy all option as default setting, see the screenshot of Preferences (section Marker Copy Option) of my Jpegcrop utility in my post in the Labels Under Thumbnails - More Options Please thread.
I would assume that Opus uses similar default, and posted statements and examples confirm this.
Regards
Guido
JPEG developer
Organizer Independent JPEG Group
Original author of the lossless rotation features 