I think Regional Influence for HW zones, or an other expansion zones, is something to consider (even if top influence just means extra items sold in a zone vendor [imo preferabbly glamour items]).
Frontlines being 1 method increasing/reducing influence, but also open-world PVE like FATEs, completing Leves, Beast Tribe Quests, Treasure Maps, etc all contribute to your GC's scoring in that zone too. New FATE systems that echo more along Hamlet Defense and XI's beseiged.
..
Doesn't necessarily have to require open-world PVP. Can be PVE competition and rankings. If they're not going to reject Faction-base PVP, the other option is to embrace it or at least give it a presence outside Frontlines queues.