I think that's a really fun idea, giving players a little commemorative emblem to mark one of those "Remember when" moments this game has been full of since D1Y1. I really hope to see more of these.
On that note you know what would be really rad? If we got this back in D2! (see video)
Please consider this Bungie.
....also not for nothing but, it would be super rad to see a "Lazy Beam"... or "Man-Meltter" emblem to commemorate that one weekend Crucible was a sweet rave party with the Prometheus lens.. That was a real "you had to be there moment" cause it got nixed pretty quick. Just an idea for similar "meta-moments" like the current one.