Spoilers My main suspects for the anomaly.

Perhaps nobody had them on the radar, because they vanished from the galaxy centuries ago.

 

...yes?

 

I've totally forgotten what this omega thing is.

 

Just so you don't have to re-watch voyager
https://memory-alpha.fandom.com/wiki/Omega_molecule

 

I did a rewatch last year, It didn't stick.

 

DMA creators could be Stilph aliens close to the galactic barrier that were mentioned in the last episode, or some brand new aliens never mentioned or seen before.

 

I was thinking the same thing. Perhaps the Doomsday Machine was mining equipment too and the USS Enterprise didn't have advanced enough sensors to pick up what the Doomsday Machine was mining.

 

More likely reformed: we see a Borg in the far future in a Federation classroom in Lower Decks, and they were Federation allies in the 28th century in Star Trek Online.

 

Oooh what if it's the "click click" aliens from TNG Schisms?
We don't know the full capabilities of their species or where they came from.

Or an angry Tasha yar from an abandoned timeline riding a Dyson Sphere of doom...Data didn't phone back after their date, so she's pissed.

 

I'd love it to be the schism's aliens. They were featured in one of the Titan novels and were pretty terrifying but I've always felt they needed another appearance on televised trek.

 

Barrier and planet shrouded has me thinking about ST5. I am hoping that it is not a reformed "God" on Shakaree

 

That's the other barrier

 

Why would our galaxy have a barrier, is that to keep things in or out, makes me think it's some kind of confinement.

 

There's a barrier around our solar system in real life as well. And around our planet in a way. Barriers just happen I guess!

 

To keep us in.

 

According to two separate novel series (Shatnerverse and Q Continuum), it's a defense set up by the Q against two powerful entities (O is in the Q Continuum novels, while a dark matter creature is in the Shatnerverse novels).

 

Yes but the good citizens of the galaxy put that one there to keep us in our own solar system.

 

I did, and I would actually like that!
They would have evolved, maybe not even be a strict hivemind anymore, and might simply not notice they are harming "lesser" species (us being the ants to their humans). Or there's a problem with their progamming which could be fixed.

ETA: I don't think it will be the Borg, though.

 

What about that dormant species that they saved in episode 5 or so?

 

"10-C" the name is probably some kind of clue from the writers.