I realise the OP in this instance is Australian, but a word of advice to anyone from France reading this, you can only obtain ONE OA visa using home funds. Any subsequent applications in your home country, require 800,000 baht in a THAI bank account
At this point it's difficult to say when the hammer will fall. There MIGHT be some flexibility given by Thai immigration (perhaps they MIGHT allow a tolerance to provide for immigration delays) but I wouldn't bank on it. In true Thai fashion there won't be an announcement until the day before!
What country are you from? If you're Australian, you're laughing with the OX visa. Five years, which can be extended a further five years, and no requirement to transfer money into a Thai bank account.