Earlier quoted context omitted.
Aptitude tests are IQ tests in a socially acceptable disguise.
Not exactly. There may be some correlation, but there are certainly people who can get in via an aptitude test who would not be able to get in using an IQ test. The testing methods are completely different.
There is so much correlation that the correlation of an aptitude test with an IQ test is basically equal to the correlation of one IQ test with another IQ test. (Around 0.8) By any definition other than "it can't be an IQ test unless that's part of its name", the aptitude tests are IQ tests. They do not differ in function.