there was no formal recall by BMW but the timing chain problem is real like it or not. do a search in Google on n20 engine failure; n20 timing chain problems; and you will see many links to people having n20 timing chain issues.
BMW also redesigned the timing chain components for a reason.
here is a link to a site with good info to the main problem with the timing chain and you will see that the main problem is the plastic components fail which causes the problem. if you think that it is an isolated incident then I would say take the blinders off.
https://en.wordpress.com/tag/n20
why it hasn't been formally recalled is because BMW is dragging it feet with the nhtsa so that they can limit the total cost of the recall since it is a very costly job at 10hrs+ to do.
also read in the comments that he doesn't have the same problem with the n55 engines. the n55 most likely does not use the same components.