since it was a mid-year OPTION for '68 there is little documentation on how it was worded, but AFAIK A87 was only available on RM21s.

then the hardtops came along & some of the components of A87 were STANDARD on RM23 (& RM27 once 1969 model year arrived)

..... but YES, all '69 RM23s should have the H2_ interior STANDARD (not the base coupe's M2_ interior)

end of year build outs may stray from the norm, and lots happen as far as parts swaps - even on nearly new or couple year old cars