Even though the MN03 lamp is considered robust, a shock isolated bezel will give it additional protection, especially when it is used as a TID. You don’t want to use the light as a TID at the cost of a lamp assembly. I guess it wouldn’t be a bad trade-off, if the light was your last line of defense.
As for the new M3, it was released early this month. Meridian Tactical had a few, but I’m assuming that they’re all gone. Email Chris just to make sure. As a last resort, I think it is available on ebay. Surefireparts is also auctioning off a new M3 bezel right now.