Virginia doesn't have "tiers" to be exact, but they do characterize sex offenses as to whether the offender is EVER eligible for relief from the registration requirements.
The minimum time before you can apply is 15 years. Some crimes are not eligible for 25 years. Sexually violent offenses, multiple offenses, and murder bar you from ever making that application.

I suspect he's never getting off the registry.

The feds do define Tiers. SONRA requires him to stay on for 15 years even on Tier I.