Your quote only describes in general terms what TIFF is. I guess it depends on what is called major. Staying within the same version is not usually referred to as a major update in software and the shortcoming has been highlighted by people much more familiar with this stuff than I am. I've just been doing my homework before making some purchases. Adobe documentation shows a couple of changes as it applies to their own programs but that's it.
"TIFF has not had a major update since 1992, though several Aldus/Adobe technical notes have been published with minor extensions to the format, and several specifications, including TIFF/EP (ISO 12234-2), TIFF/IT (ISO 12639),[4][5][6] TIFF-F (RFC 2306) and TIFF-FX (RFC 3949)[7] have been based on the TIFF 6.0 specification."
Additionally, a quote from a link off of the Adobe site...
"The TIFF format is owned by the same company that also owns PSD though, and as such, it is not very surprising that it has been more than a bit neglected over the last decade or so. That is probably the single most important drawback of TIFF: it lacks standardized support for advanced imaging features that were developed over the last couple of years."
As I indicated, any huge advances will probably come from someplace other than Adobe. Perhaps here
http://www.awaresystems.be/imaging/tiff/bigtiff.html