Does anyone have any insight as to why this is?

Dunedain cache ( http://ringsdb.com/card/02097 ) functions exactly like all of the other signal attachments, but is missing the signal trait. This is a bummer for weather-hills watchman and rune-master.

Could this be eratta'd?

Thanks

It does seem odd, and I admit I've used Dunedain Cache with Weather HIlls Watchman, not noticing it wasn't a signal like the others in the family. With that said, the cache is of weapons, while all the other signals are more abstract. Still, if that's the thematic justification they could at least give it a "weapon" type so it can be exhausted for various effects. It's not like 2-cost is cheap just to add ranged, especially when it doesn't work with the cards you mentioned.

No chance of errata to make it more useful. Aside from misprinted cards, positive errata just doesn't happen.