Also, notice the theme of the Foehn origin mission names.
1) "Nobody Home" - there's no sign of life, probably due to the "hibernation".
2) "Kill the Messenger" - Someone spots Bastion base too early, so obviously you want to off them before they alert Yuri.
3) "The Remnant" - ...I think this one speaks for itself.
Whoops on the Bastion location, I somehow missed that. I do remember Haihead's loading screen being a confused mess though, which makes sense if they don't actually have their own base of operations (either because they're based in Bastion as well, or because their operational doctrine is more akin to guerrilla movements with no fixed abode) and Epsilon are still hunting for a base that doesn't exist. Hard to miss the massive great hurricane surrounding Coronia though...
Another reason I'm betting Foehn's development proper starts in Act 2 is because at that point Yuri is a clear and serious threat rather than this vague oddity skulking around in the shadows and only showing hints of its ulterior motives known through a handful of seemingly disconnected anomalies. He wasn't exactly open until we hit Moonlight, so expecting someone to think "hey, there's a massive threat that we need to build a whole new army to counter" before then might be expecting too much.
...Of course, I could just be barking up the wrong tree in the wrong forest again.