Maybe they do it by last name, alphabetically? I'm a W.
From previous score releases over the last several years it appears that the emails and associated pdf disclosure downloads being available on the LSAC webpage are done in batches by test center. Meaning one test center per batch that the LSAC computers put out/make available.
Whether the order of release is by geographic location of the test center, say east coast to west coast, or by test center # is up to LSAC and not disclosed.
PS: It certainly doesn't help the LSAC staff and their servers that are sending out the stuff speed up the process when people keep refreshing their browsers on lsac.org ~5 times per minute, thereby hogging bandwidth and server time.
Just a random guess, maybe if people would stop hitting refresh over and over in an OCD manner the stuff would get delivered faster...