One of the things to recall about TNS is (to my mind) it functions more as AP/Reuters than your local news channel. Or if it does include local events, they are streamed into a different feed.
If you think of how much news there is to consume on different sites on Earth (even major headlines vary from CBC, Fox (ahem), CNN, BBC UK, etc. And that's the big headlines. If you count all the gossip and entertainment, etc. then the amount is staggering (for any given day). Then assume you are getting feed data from off planet with important and more trivial data. The volume would be a tidal wave.
I look at TNS as:
a) Happenings of import (invasions, fleet movements, red zone establishments, etc)
b) News about the nobles (aka Imperal Govt) and the planery gov'ts or aliens
c) Key matters affecting Imperial, sector or subsector trade, law or relations between polities (or relations with other star nations)
Anything else would be relegated to some sort of planetary feed system broken into various categories.
Your aggregator, with sector wide settings, and broad areas of interest, could likely pull thousands of news articles a day. You'd need to have a picky AI or a big staff to weed them.
Tom B