The Sussex FA said that FA cup competitions take precedent over the Sussex Challenge cup. We are involved in two FA cup competitions this week, ie the U18s last night, and the 4th round on Saturday which will probably involve some of the U23s.
This article said the postponement was agreed before last night's match and it was the Sussex FA who pulled it, not the Albion.
https://www.theargus.co.uk/sport/17376142.sussex-fa-defend-albion-postponement-after-eastbourne-town-anger/