From LATAM SM today:
Unfortunately, this update is taking longer than expected and your account may be inaccessible until the 16th of May, but rest assured that we are working hard to finish before that day.
So we can expect it to be out of service until at least the 16th.
(I do though notice I can now access some information via the phone app. Though it's lost my logon details and all of my entered flights. Buch of f**cking amateurs.)