What Zovaal knew.
During the Endtime dungeon, Muro claims that the hour of twilight is a blessing compared to the “true Endtime”
So the void lords corrupting Azeroth’s world soul is better than some other apocalypse that Muro witnessed.
Then Zovaal claims that a cosmos divided will fall against what is to come.
So I assume “what is to come” is what Muro prevented with the hour of twilight.
Will we find out what that is during 10.3 when our nozzy fully turns?
Entropy and heat death of the universe?
Safer to suspect the Old Gods are tricking him into creating the Black Empire. A bit meta but the writing for most mysteries has been rather lame. 
The End Time dungeon was Azeroth some time after Deathwing succeeds in killing everything. It did not depict the Void Lords corrupting Azeroth’s world soul. It’s more likely Murozond witnessed the Void Lords corrupting Azeroth’s world soul much further in time after “The End Time” that leads him to say that what we see in the dungeon is a blessing.
Deathwing succeeding is the hour of twilight.
DW worked for the old gods.
The old gods goal is to corrupt the world soul into a void titan
So it’s safe to speculate that Endtime was post world soul corruption, or just before it.
That is not at all what the dungeon says it is. The Hour of Twilight was the present day in our time line. The End Time was an alternate future. It is likely in that alternate future the events of The Hour of Twilight never needed to occur.
Probably more like this happened among the writers.
“So what is Murozond’s motivation here?”
“Hu?”
“Why is he fixating the time lines on the End Time?”
“Ummmmm… Oh I know, because there is an even worse future he’s trying to prevent.”
“What can be worse then what we’ve depicted?”
“I don’t know, we’ll figure it out later.”
ENTROPY FOR THE ENTROPY GOD! WASTE HEAT FOR THE WASTE HEAT THRONE!
Honestly, though, that fate is so far in the future that it’s not worth sweating about. Even those who are allegedly immortal will forget about it and rediscover it about a hundred thousand times before it actually happens.
well, in a fantasy world it might just happen next week or something. You know those anima consuming aliens in shadowlands? They are eating suns right now, probably.
Au where the HoT DID happen. That Muro as literally DWs mission.
Compare the horde gun ship ruins in endtime and the one from dragon soul that DW totals.
So Endtime is essentially what azeroth would look like if it happened.
Yogg-Saron’s Whispers focus on Ny’alotha, the Sunken City(which is hinted by Deathwing in his Annotated version of The Old Gods and the Ordering of Azeroth), the Black Goat, the Great Rook and the Black Forest.
N’Zoth’s Whispers focus on the threats that are immediately heading our way. Infact when we go back in time in the Thaldraszus Questline he immediately gives clues to the events nearest to our Time Period focusing directly on the Dragonflight Expansion and the one whose Dreams sing beneath the surface(the Void’s Dreams and the Void’s Song).
The Void’s Spells in Aberrus are Astral themed meaning that Night is indeed a Void Entity whose song sings beneath the surface. Of course as Gloomseeker Yarga puts it: “There are many things darker than Night.”
As the prophecy of Barrowknoll Cemetery states: “Night falls! Her song will end!” and as N’Zoth states: “The fall of Night reveals her true face. She will bring only ruin.”
Personally I expect Xal’atath to be Night herself considering the disparaging(not to mention blatantly jealous) remarks she makes concerning Elune(she also insults N’Zoth quite a few times despite noting how things usually work in his favor so Elune is not the only one to be insulted by her).
I like how the blue dragons have a history of going crazy and being infected by demons and everyone suspects the bronze to be the ones at fault. Like yeah no doubt murozond is the guy who makes a mistake, but I wouldn’t be surprised if it turns out his big mistake is not killing the blue who pulls the trigger.
zovaal “knew” nothing because they haven’t written what he “knew”
he’s a bad character and they just gave him that line because they thought it sounded cool.
Poopy character aside…
They clearly have some cosmic threat planned, and that line was most definitely a bread crumb.
It seems something is coming that will be disastrous against all 6 forces in which each one feels that their domination is best case scenario.
So void = hour of twilight, aka void titan azeroth
Death = w/e 1000000 iq plan zovaal had
Etc.
I mean that goes for all type of story telling.
i think Zovaal is one axis higher than Murozond.
And behind the door…is another door. 
Is he though? What’s stronger than time travel?
titans see outside timeways. Amanthul for example has the power beyond Murozond, and is the one who gave Nozdormu his power.
if Zovaal is “titan-plus”, then it’s expected that he at minimum has titan-level power. Power such as… time-scrying? or being immune to temporary shifts?
sadly that character was developed so little that we don’t. know what powers he has.
we spent two tiers convincing him to put a shirt on.