Bummer on the crash, yes the car kept you safe. Your description is textbook "stop and go" traffic that's caused by resonances in traffic following, an accordion effect. If you ever have to come to a complete stop on an Interstate, you can be damn sure there will be another to follow. Chill out and let the accordion settle down in front of you, or you'll repeat this.
Read this research study conclusion.
Something I find interesting is the impact was fully above the crash beam. All these big SUV's and trucks with their ass high in the air leave no place for forces to intentionally dissipate in a crash. Theoretically it would be better to standardize a crash beam height, front and rear, but I fear it would result in everything being Tahoe height, and I definitely don't want that.