Seems I got the release date wrong, whoops on my part. I remember reading a book on various video game systems and it mentioned the PS2 coming out in 1999, the date stuck in my mind from that but it must have been a mistake or a planned release that got delayed.

As far as I know there's no way to update the firmware on PS2 systems. The updates came out as hardware revisions were made, not all hardware is compatible with all features. I could be wrong though.