I think it may be a copy/paste error in MK82F25615.h. The preceding definition was the System Register File, which is defined identically to RFVBAT but is, indeed, 32 bytes:
/** RFSYS - Register Layout Typedef */
typedef struct {
__IO uint32_t REG[8]; /**< Register file register, array offset: 0x0, array step: 0x4 */
} RFSYS_Type;
I assume I can safely change the VBAT Register definition to occupy 128 bytes:
typedef struct {
__IO uint32_t REG[32]; /**< VBAT register file register, array offset: 0x0, array step: 0x4 */
} RFVBAT_Type;
I have no idea how to report errata in MCUXpresso SDKs. If someone from NXP is reading this, please let me know.