Mine was purchased in October 2020. Not sure of the actual manufacturing date, but well before March 2021I took my R18 Classic in for the 600 mile maintenance yesterday. It was bought in August. They said there were no recalls. I haven't had the whine.
It looks like there was a change to the R18 at some point with two versions. Go to their Installation Instructions page here https://www.bmwmotorcycles.com/en/service/manuals/install-manual.html and select R Models, Heritage to see R18-OL11 and R18-OL13 and R18 Classic-OL21 and R18 Classic-OL23. I read somewhere that the second version came out in March 2021 (I might be wrong). Has anyone took a survey to see if those experiencing a whine had a manufacturing date prior to March 2021?
Tom