It doesn't always take high IQ thought to produce high achievement. In fact, we should be focusing on performance according to NSGT. The definition of Gifted and Talented according to NSGT:

(quote)
This definition of giftedness is the broadest and most comprehensive and is used by many school districts. It speaks of talent, which includes all areas of a child’s life: academic, artistic, athletic, and social. Most schools limit their definition and their programs to academics, but it is important to focus on performance and accomplishment. It is not enough to just have the talent; you must be using that talent to achieve at remarkably high levels. However, this definition does also recognize that while all very talented students have the potential to achieve at high levels, some may not have yet realized or demonstrated that potential. Such students may be underachievers, twice exceptional, or represent underserved groups who have not had a nurturing environment to bring out those talents. Finally, this definition is a comparative one; these students achieve or have the potential to achieve at levels way above their peers.
(end quote)

Personally, I have no problem with lower IQ students in a GT class / program so long as they can be productive, they can keep up with the work, they're able to stay emotionally healthy, and they enjoy the program. It's important that a well trained professional in GT be heading the identification program and evaluate students in that program to ensure they're not doing themselves more harm than good.

The whole thought pattern of "Levels" of service seems to be missing in education. The idea being to help each student to their potential with services that they require to do so without burdening them with what they can't handle. Readers here understand that even at this end of the bell curve the level of service needed to do that is quite extensive and varied.