Before anyone else jumps on this, remember that there's already another Siacoin ASIC being shipped from
https://obelisk.tech/ They're already doing batch 2 so the hashrate might already skyrocket before these Bitmain ones even ship out.
A3 is being shipped out, received a shipping notification through FedEx Delivery manager for delivery on Monday

Obelisk batches are scheduled to be shipped in June and August.