AP Statistics is a very valuable course, may provide a GPA boost, and will most likely help with course work at the next level. My DS took it his senior year after having completed AP Calc BC his junior year. I would also suggest AP Java or other computer courses to fill the gap.
On a slightly disconnected note AP Psych helped my son a lot in his non-major college Psych course. If I were to advise my older boys now I'd have them take non-major AP courses and concentrate on getting a 4 or 5 on those tests. For example AP Euro, so as to not have to take the history requirement while attempting to pass computer science or engineering courses at the collegiate level.
On the math question, I agree with AP Stats.
Why not work backwards from his target schools, and see where else he can Senior Year Schedule Arbitrage? What other AP classes, particularly humanities and non-STEM, can he take the AP version that will validate at civilian colleges and USNA? My DD is at USAFA. She validated 7 subjects, 8 total USAFA courses for 2 language requirements, and arguably like 9 if you count placing up into honors Calc 2, freeing up her schedule and getting to fun majors classes earlier.
Course Validation Policy page for Academics at USNA.edu. Updated Wed Jul 20 13:09:33 EDT 2022.
DS is registered for AP Stats senior year. He was just looking at how to fill his schedule with things he finds interesting and that could help get into the academy. With the way the schedule at his school works(because of overlapping classes), he hasn't been able to take more than 3 AP classes each year since grade 10.
This is what he has so far
Math - Algebra II, Geometry, Pre-Calc, Trig, D
nrollment University Calc A/B, AP
Science - Honors Physics, AP
English - Honors English, AP
English Lit, D
nrollment University Writing, D
nrollment University Literature
History - Honors Civics, AP
US History, World History/Geography(He enrolled in AP
Euro but it did not fit in his class schedule)
Other - Exploring Engineering, Engineering Design and Prod Dev, Applied Engineering, World Language, plus graduation requirements including Art, PE and Health
Majority advice seemed to be AP Stats. Thanks you all.
Senior year he is registered for AP
nrollment University Physics and AP
Microeconomics. Filling in the rest is the dilemma - in addition to finding a way to continue on the advanced mathematics route.