Who's going to provide support?
Software is supported by the software vendor. Hardware by the hardware vendor.
If it's not sold as a bundled system from a licensed VAR, then there wouldn't even necessarily have to be any official support. "You want support? Buy a bundled system from a licensed distributor". It's a tradeoff that I want to be able to decide if I'm ready to do by myself. Many hardware and vendor options, and some of them will give me official support while others won't.
It's feasible at any stage, but one of the most important priorities right from the start should be to offer your customers options and make AmigaOS a more attractive product by having it run on as much hardware as reasonably possible.
Personally I have never ever used any official support channels during all my years as an Amiga user, neither before nor after Commodore's demise. (Was there ever any?) There's always you guys!

It seems a whole lot of people suddenly got worried about support after it was mentioned on amiga.com...
Why even bother getting the Mac? Yeah Mac has much higher end CPU models available, but at a price. Once the A1XE is shipping it should work out to the same.
Yeah, why bother with alternatives. Things would be much better if we could only buy one OS from one vendor and one piece of hardware from one vendor, and we'd all be driving black Ford Model T cars...

Choice, pricing, competition, development, quality, personal preferences, such irrelevant things...