8K wasn't available at the time of the 2004 SE. 4K was, but it wasn't yet widely used for home video--though it was widely used for films intended for theatrical exhibition, which would include the SE since this is effectively a new negative. But no, not even 2k, which had been in place since the 1990s. Oy. But if you think about it, its consistent with his feelings at the time--Episodes II and III were shot on 1080p resolution as well.

TPM is the one caveat in that it was scanned at 2K resolution, which was the highest resolution possible in 1997 when the live action was processed. It was shot on film, of course, but, since every single shot except one had to be digitized for an effect in it, the negative for TPM, which is probably saved in a computer, is only in 2K (the actual physical negative, since it would have been made from a computer print-out of a 2K scan, would be actually lower resolution).