Lorda got a huge rush of players at the start because of: World PvP while leveling, Fresh server all "equal", big initial population draws even more people in etc, "progression" etc.
Then you get people stopping and losing interest: all the factors i mention for the starting rush disappear (and people realise progression pve is just the same old boring easy repetitive pve, and the tuning doesn't really make it any harder, just makes it requires more gear and a little more competence in coordination and raid composition.)
Furthermore In the case of lordaeron, it was clear by 70 cap that it was a custom server, custom forcing you into pve by removing pvp vendors without any similar limitations on pve gear, this also took a chunk of population out of the server.
The population will keep falling. Maybe pve will be made regular easy mode instead of hard easy mode, maybe rdf will be added, but none of this will help significantly. At some point it will be decide (again) that the pet project server has served its purpose, then lordaeron will be merged with the high rate server(s). This may be a couple of years away, maybe more, but this is ultimately the future of lordaeron.
After the merger they might re-make the 1x server for progression again.