I also got my S&W letter today but I had already checked it myself (GTG) and just a few days after the ALERT was issued I got a call from my LGS that sold me the Shield asking me to bring it in for their inspection-which I did. Gotta love that store, still GTG.
The letter is now in my original S&W cardboard
box for documentation purposes just in case the trigger goes haywire in the future.