Three connectors are built but not yet open to everyone, each for a different reason.
Shopify
The aOS Shopify app is in Shopify's app review queue. Until it's approved, stores can't connect themselves.
There's nothing to do on your side. Once approval lands, connecting a store will work the same way as the other per-client connectors.
Etsy
The Etsy connector is built and waiting on Etsy's commercial API access, which is their approval process for apps that read shop data on behalf of sellers.
Same as Shopify: nothing to set up in advance.
Meta
Meta ads data is available now, by request rather than self-serve, while the aOS app completes Meta's review.
Contact support to be added, and mention which Facebook account manages the ad accounts you want connected. Once you're added you'll be able to connect Meta from Settings → Integrations as normal.
What to use meanwhile
If you're planning demand or inventory for a client selling on Faire, that connector is live now. See Connect Faire.
For your own agency's financials, Xero and QuickBooks are both live. See Connect Xero or Connect QuickBooks.
Will I be told when they open up?
Yes. These are the connectors most people are waiting on, so availability is announced rather than left to be discovered.