First thing we've found so far is a statement by then-Supervisor Joe Simitian on 10/24/08 on County letterhead:
During the past 18 months some members of the public have proposed that we use this GUP and Community Plan process to establish a "cap" on the University's maximum development potential, "buildout" as it's often referred to....I am not inclined to to propose that our Board establish a permanent cap or attempt to define at this point the ultimate buildout of the campus.
I am inclined to think, however that it would be irresponsible to simply ignore the need for a clearer notion about the ultimate capacity of of Stanford lands and a clearer vision of what such a plan might entail. For that reason I'm inclined to suggest to my colleagues that the Conditions of Approval for the GUP include a condition requiring that Stanford undertake a Buildout Study regarding the buildout potential of Stanford University on all unincorporated lands within Santa Clara County.
So from the beginning, "cap" = "maximum development potential" = "ultimate capacity of Stanford lands" = "Buildout Study". The Buildout Study was later renamed the Sustainable Development Study.
The next thing we found in November 2000 was tying the Buildout Study to the Compact Urban Growth standard that would've limited growth beyond the Academic Growth Boundary for 99 years. That time period limitation later shrank to 25 years.
Still later, November 22, 2000, then-Supervisor Beall proposed the new name, "Sustainable Development Study" that broadened the scope of the Study somewhat. While somewhat unclear from the document I've got, he may also have inserted the Community Plan language "it would be infeasible to accommodate an additional 200,000 square feet annually in perpetuity, in is unclear how much additional development is appropriate." This is a statement about the foreseeable future with no end date. The Study is supposed to address the question of "how much additional development is appropriate" without an end date.
The final change follows a letter from just-elected-to-the-Assembly Joe Simitian, requesting the term "maximum buildout potential for all fo Stanford's unincorporated land" be placed in the Stanford Community Plan, explaining that the concept was part of the conditions for the General Use Permit. The term went in.
Nothing suggests the idea ever restricted the vision from the original idea of determining the ulitmate capacity of the land for the forseeable future.