You can't learn the same information by "reading between the lines" of changes that they make to the software, because until they actually distribute anything that is built from those changes, they don't have to put those changes anywhere where you can read them.
For example, it's fairly common for new chips to be accompanied by a set of patches for GCC to support them -- which have been obviously developed over many months, but which aren't sent upstream until the new chip is announced.
Also, in practice reading between the lines is hard. My understanding is that, back when Apple was considering switching from PowerPC to x86 and this was a deep, deep secret and anyone who found out would have had the scoop of the decade, Apple still released occasional x86 fixes to GCC ... and everyone apparently assumed this was just about Darwin.
Re: A requirement to post FLOSS software usage?
For example, it's fairly common for new chips to be accompanied by a set of patches for GCC to support them -- which have been obviously developed over many months, but which aren't sent upstream until the new chip is announced.
Also, in practice reading between the lines is hard. My understanding is that, back when Apple was considering switching from PowerPC to x86 and this was a deep, deep secret and anyone who found out would have had the scoop of the decade, Apple still released occasional x86 fixes to GCC ... and everyone apparently assumed this was just about Darwin.