Could you give some examples of this? The major 2015-2017 storylines that I remember were, in rough order (though with overlaps, of course):
- murder of the Emperor / attempted murder of Halsey, leading in to...
- ...establishment of the Powerplay characters (including, later, Dangerous Games)
- early alien mysteries (UA, Barnacles, Guardians) and cover-ups (Black Flight, Palin)
- founding of Colonia
- Premonition (including the conclusion of the Formidine Rift search)
I can't think of very much in those which isn't also being done now with the various current storylines, and plenty that wasn't (no doubt only due to technical limitations) done back then that is now, in terms of making the lore and plot have both in-game relevance and on-forum discussion.