As a veteran player, the game is dying if not dead; at least for me. I only log in every once in a while because there is just nothing new to play. The new dungeons are locked behind campaigns, which i find not fair. I feel a better way to get players to play through a campaign, is not to lock the dungeon but rather have it give new rewards as players progress through a campaign.
For example as i'm progressing through chult, tong should give new rewards. More brave for example, or new gear. Or rp. The point is you should be able to queue for Tong from the start.
With that in mind, i think the next mod should just be to add new dungeons, skirmishes, and trials that are ready to be played day one. Say one new dungeon for each zone, and have them give rewards that reflect a players campaign completion to give newer players more incentive to complete a campaign.