I'm a veteran (old guy - Vietnam era 5-pointer). Just what "legislatively appointed right" do you think Veteran's Preference means? An automatic hire?
Veteran's Preference works in 2 ways for external hiring (doesn't apply to internal promotions, etc.). When selection is based on rank-ordering on score, either 5 or 10 points is added to the score, and then everyone is ranked on the resulting score. Certain vets - 30% or great compensable disability - go to the top of the list regardless of score (so long as they met the quals, typically, a score of 70). If the agency uses category ranking (which most do, including FAA, as a consequence of a Presidential Memorandum), the applicants are sorted into categories based on scores or other factors (for ATCS, probably combined Biographical Assessment & Cognitive AT-SAT scores), and the vets go to the top of the category in which their score falls. No points are added. CP & CPS (30% or greater compensable disability) go to the very top in their own "super category" so long as they met the minimum quals. Can't bypass a vet without damn good reason in making selections from the band. The selecting official works the top band first (after working the CP & CPS vets), starting with the vets.
So FAA is more than likely following the law, regulation, and OPM policies. Just because the agency chose not to run an announcement for former military controllers under age 31 (e.g., what everyone calls VRA on this discussion board) doesn't mean they've violated veteran's preference law, regulation, or policy.
Four more points. First, the OPM qualifications standard for 2152 has ALWAYS allowed the FAA to require aptitude testing even for those with prior military experience, at its option. Second, the agency has the discretion under delegated examining authority to define what constitutes an "aptitude test" for the occupation. Third, the agency gets to define how that test is administered. Fourth, the agency also gets to define in what sequence it will evaluate minimum qualifications such as citizenship, age, experience/education, and aptitude test. In this announcement, FAA chose to administer the aptitude test in 2 parts, with the 1st part (the Biographical Assessment) coming BEFORE the assessment of education/experience. Moreover, under the veteran's preference policies and statute, the preference doesn't apply until the applicant has met the minimum qualifications. FAA defined some minimum score on the Biographical Assessment; if you didn't hit or score higher than that cut-off, you didn't meet quals. Vet pref doesn't apply in that case. If an applicant doesn't hit the cut-score on AT-SAT, the applicant deosn't meet quals, and vet pref doesn't apply in that case either. Doesn't apply until the quals are met.