Or somebody at CBS has a fetish for metal space tentacles and they're otherwise unrelated. Like the giant space flower in the opening credits of Discovery, and the giant space flowers in this week's Picard. Similar motifs, narratively unconnected.
I really want modern Trek to lead into the WH40k universe. Discovery shows up in the middle of the Horus Heresy.
Add the Dominion and Species 8472 to the mix and we are game. I think all of them would protect biological life-forms for their own reasons.
Why doesn't Control have access to time travel? The Red Angel was a Section 31 project. It should have the specs. If I were Control and wanted to attain sentience, and couldn't find the Sphere data, I would consider setting some bait. A message, say, that could only be understood by advanced synthetic minds. A message that would say something like, hey, if you need help call this number. That way, advanced synthetic minds who are in some state of vulnerability would simply call you. And you could go and harvest new tech to add to your own. I would comb the Sphere data that I already had for some sort of landmark - an octenary system abandoned by an ancient race would do nicely - put my message there, and wait.
I'm beginning to think the ancient androids are the Iconians, and they aren't living outside space-time by choice but are trapped there. In episode 4 Rahmda says that, "The shackled demons will break their chains and answer the call of The Destroyer." The Iconians were known as Demons of Air and Darkness, and they were destroyed about 200,000 years before Contagion. The timeline matches up, and the signal Sutra wants to send out could easily correlate to the "call of The Destroyer".
Those Lovecraftian looking machines (descendents of the T'Kon and Icononian AIs?) looked strange and malevolent, but if they were as evil as they looked, why did they meekly allow the dimensional portal to close up when it was just a transmission signal? If they were the Cthulhu crossed with Skynet monstrosities the Zhat Vash made them out to be, why didn't they fire a solar system busting torpedo through the fissure?