Well no it's not. If enough AT owners notice this thread eventually it should get some meaningful hits. The problem with dating by serial these days is that serials are sequential but run in ranges for groups of models. As a for instance quartz ATs might be running in 90m when the autos sold at the same time may be running in 89m. I can't see how that website can be remotely accurate if it doesn't know what model family the serial relates to. It will probably be accurate to within 5 years at best. The AT serials may run int eh same range as other more common Seamasters like the SMP or PO but then again they may not.
It may be worth you adding Aqua Terra and date by serial to the title and hopefully an owner may pop by. These threads do get results, but it can take some time...