It's not a vague bulletin. Every N63 out there is getting this work.
Just got mine back. Took 9 days. You will get loaner - push for something nice.
I'm not 100% sure but I don't recall seeing anyone in those threads who has had the timing chain changed.
Huge threads on this:
X5 N63 engine recall (Service Bulletin B001314)
N63 Engine Recall/ Service Bulletin - Bimmerfest - BMW Forums