All valid points. But perhaps a concise colour-coded feed, with symbols could prove to be even less intrusive. Instead of "___ killed by ___". We could have "___ * ___".
The * would represent a symbol of the gun. It would save space, be easier to recognise at a glance, and overall, help the experience.
Why not let people toggle it on/off, or toggle the colours?
Even if creating a specific symbol for each weapon is far-fetched, a colour-coding system would be quite feasible, at the very least. Please 343i? Hope you're listening! It's only a minor tweak that I'm sure we'd all appreciate!