Hamlet Defense (or at least the DotH/DotL side) was replaced by simply turning in gear at your GC HQ whenever you want to, rather than having to wait for a scripted event to play, which of course players then exploited to rapidly level their crafting classes based on the requested gear being submitted (theoretically you're meant to craft the gear being submitted yourself, but few do).

The fighting side of Hamlet Defense became the reoccuring series of FATEs in ARR areas that have a failure flag (the battles against qi'qirn and amal'jaa at Highbridge in Thanalan, protecting the pirate base in Old Maid's Mill in La Noscea from kobolds, and the battles against duskwight thieves at the ruined village of Highbury in the Black Shroud).

It's clear SE simply aren't interested in that large scale content anymore and want to keep crafting and gathering classes seperate from battle, so I do not see them changing this.

Also we kind of got the 'crafting airships' content eventually too... but as far as waging PvP battles with them, I doubt SE will end up going that far.