I think this is all down to what people expect the company to...

I think this is all down to what people expect the company to announce. The company (via AM on Twitter) stated that they were 'on the cusp' of BG, but just required the gas to be switched on. Marketing Man is quite right in assuming that 4 weeks down the line, there has been ample opportunity to test that theory. However, as you rightly state Luke, producing BG and producing BG efficiently and consistently are very different things, and we can't impose an uneducated timeline on that. I wouldn't expect the company to announce BG until they know they have the process down pat.
IMO BG has been produced, but their process is still going through refinement. It would be irresponsible of management to announce BG until the process is perfected.