I don't think they can take away the GIEP, but they could basically "do nothing" at the GIEP meeting since they consider the acceleration to be the final answer.

It might also depend upon your school district. Around this part of PA, many districts say you must meet the FSIQ >= 130 to qualify as gifted. Many districts do not accept outside testing. Our district does not accept outside testing, they switched tests a few years ago to SB-V from WISC-IV (some studies say scores are lower on SB-V than other tests), they do "pre" testing and say your kid will never hit 130, etc. Basically, they do everything they can to discourage pursuit of the gifted label.

Is the GIEP based upon FSIQ >= 130, with IQ testing by the school?

I didn't look back at your other posts, but did the school suggest the acceleration? Are there other alternatives to the grade skip? Are there a lot of gifted/bright kids in the district, so that eventually classes will be differentiated (by middle school or HS)?

I would try to keep the GIEP in place, but I understand that even if one "takes as break" from a GIEP, it can be revisited later without going through new testing. Take a look at the PA Code and good luck. My older two didn't get labeled until 7th grade, and then it was just so they would get automatic entry to a certain HS course.

And yes, you can be gifted and not have a GIEP. You do not need to sign off on the GIEP even if the school IDs the child as gifted.