I've seen the current pattern over a lot of MMOs. Assuming you can apply those other games to GW2:

Cantha and its sudden announcement after a year of so of "no more expacs" is a last money grab to satisfy the bean counters before they ramp down the game's production to cater to the ride or die crowd who will be playing until the servers close. The audience of people who already have all of the raptor skins and are happy to get a new chocobo one. The constantly rising cost of things in the TP makes it obvious that the population is shifting (or maybe even has shifted) to a collection of vets who have been accumulating currencies for near a decade now and aren't going to go anywhere.

That's why the D.R.M.s seem like such low effort stuff at the moment compared to what has come before. It's the model for the post expac life of the game: Frequent releases of bite-sized repeatable stuff.