Hello,
i am a metric lover, you can know a lot and predict nicely when looking into metrics.
one thing's sure, no official sources for numbers and no numbers are the same nowhere,
but looking into trend, and knowing BioWare love metrics, thier decision on having a bonus wave today will reveal if everyone going to get access tomorrow or not.
let say that almost half all the preorder have been invited. 1/5 yeaterday and 4/5 today.
if this is correct (and it seam) and if they add a bonus wave of invites today, then tomorrow will mean everyone will be in. ( is that 5 days early access for everyone??)
one thing to not forget.
if they have not tell us now, it is because the formula they use to decide have reach its limit. at the moment someone ( a team) is certainly doing a risk analysis to figure out. that explain why it is so long. but truely, they will take the decision and it is not more about servers performance than about nbr of people present in the same area to keep the game enjoyable with mobs to kill.