Lifetime statuses in general are ambiguously prioritized.

For example, a DL lifetime/"complimentary annual" Diamond (3 million lifetime miles) would always be prioritized ahead of a Diamond who didn't qualify for lifetime Diamond for complimentary upgrades on short haul; however for global upgrade certificates, while the lifetime Diamond would clear with higher priority, their window to use will be shorter (since a lifetime Diamond would get a certificate for the 2025 elite year on February 1, 2025 that must be used by January 31, 2026, while someone who got Diamond by the regular route would get their certificates when they qualified and those certificates would have the same expiration: someone who made Diamond in January 2024 would thus have more than twice as long to use)).