I made a typo in my post - I meant to say that Blizzard has confirmed that starting with Dragonflight the stories are NO LONGER are going to be self-contained. They are moving away from that is what I meant. Apologies, that was written in mobile and my fingers slipped. I am on desktop now.
Anyways, you still haven't explained why you think Void 13.0 or 14.0 is too soon.
With that being said I think what we need to do is break up how the WoW Dev team looks at their previous expansions and expands on the lore moving forward and plans it out. Every long-term project has a long term schedule that is already decided in advanced for the most part, unless something crazy happens. I am pretty positive they have at least the next 2-3 expansions planned out. Anyways, let's break down the WoW's expansions and how they got where they are now.
First expansion was TBC which was 2.0 and it looked like this -
2.0 The Burning Crusaade - It started 2 plotlines, the Draenor and Burning Legion
3.0 Wrath of the Lich King - It started 2 plotlines, the Old Gods and the Scourge/Death
4.0 Cataclysm - It Started 2 plotlines, the Dragons and Elemental Lords
5.0 Mists of Pandaria - It Started 2 plotlines, the faction war and the Sha
Ok good we now have the foundation - re-read the above carefully if you need clarification. Now let's look at th next set of expansions
6.0 Warlords of Draenor was split from the Burning Crusade from 2.0. The Draenor expansion also introduced the Light plotline.
7.0 Legion was LSO split 2.0 which makes it a direct sequel to The Burning Crusade. However, this was also the expansion where the Void Lords started showing up another new plotline alongside the Light.
so it went like this 2.0 TBC > 6.0/7.0 Draenor and Legion + 2 New Plotlines, 1 from each expansion.
8.0 BFA was split from 3.0 and was about the Old Gods with N'Zoth being the final boss
9.0 SL was split from 3.0 and was a direct sequel to Lich King which closed up the death arc
Alright let's gready ready for the big drum reveal moment....ready?
You guessed it.
10.0 Dragonflight is a direct sequel to 4.0 Cataclysm re-awakening the Dragonflights and helping them gain their power back, but it's also opening up a new thing, the Titan plotline
11.0 Will be about the elementals which also stem from 4.0 Cataclysm and then the Dragonflight/Elemental arc will be finished and put to rest.
So what's 12.0?? You guessed it, follows the MoP plotline of the Faction War. No clue if there will be a new content here or how this will play out, but a faction war plotline will continue if this plot logic is correct. Yes, I know we have allinace/horde cross-play now but that is a quality of life change for the ease of conveince and people to play with their friends. This won't relate to the plot in any shape or form. Perhaps it could be a faction "war" where alliance/horde are actually helping each other instead, but that's just speculation/guessing.
13.0 will follow the Sha plotline most likely because the Sha were quite important in MoP.
So where does that leave 14.0, 15.0 and 16.0 and beyond?
If I had to guess 14.0 will be the Void Lords/Old Gods. Old Gods are always involved in everything trying to cause chaos and pit everyone against each other. Truth be told, they are involved in many of the previous expansions, especially Dragonflight. I mean there is a quest that takes you to the old azeroth where the Black Empire is in power via time-travel. A lot of expansions do small hints and build up other plotlines at a smaller pace, but certan expansions actually make a it the main focus. In Dragonflight's case the big focus are the Elementals/Titans/Dragons and there is a lot of Old Gods stuff too, but its more behind the curtains.
15.0 could potentially lead up to a Light War and 16 I have no clue, the last thing I can think of are the Titans.
Anyways....those are predictions. I hope painting this picture out a bit bigger shed a bit more light of where we at with the plotlines. There is 100% a pattern too it and I hope this breaks it down enough for ya. Let me know what you all think!