The ambiguity of Dalaran’s allegiances is one that could make on grit teeth.
Considering the readmission of the Sunreavers, a supposed “Horde” faction, this would mean that the Sunreavers is in fact, an “Alliance” faction.
Dalaran is a city, not a faction, and therefor can not have allegiances. The Kirin’tor is the faction that inhabits Dalaran, and The Sunreavers and The Silver Covenant are both Kirin’tor factions.
When Khadgar came and took the Kirin’tor from Jaina, and then having the Sunreavers readmitted into the Kirin’tor, the whole allegiance thing became muddled.
The Kirin’tor is either neutral or alliance aligned, leaning more towards neutral because the sunreavers can not be Horde and Alliance aligned simultanously. They can certainly have leanings of preferences (We know that Aethas Sunreaver himself was loyal to the Kirin’tor and Silvermoon City (Blood Elves), but disliked the Horde, hence why he wanted to draw more Blood Elves out of Silvermoon and thus out of the Horde, and into the ranks of the Sunreavers, the Kirin’tor), but considering that neither the Sunreavers or the Silver Covenant act without direct approval from the Kirin’tor, it is safe to assume that these personal leanings can be disregarded.
I still think that people are too fixed on the idea that Sunreavers and The Silver Covenant represented and housed either big faction back in the day, “They must be either faction!” nah, they are neutral parties who advocates for either big faction. But they are a part of the Kirin’tor, which is the neutral faction controlling Dalaran.
Just taking the whole Kirin’tor council meeting into account back in the book: “Tides of War” where the Kirin’tor council leaders met up and had to decide whether the Kirin’tor should involve themselves or not and debated the matter. If the Silver Covenant were really just ‘Alliance-4-l1f3’ surely Vereesa at that very moment would just have thrown the Silver Covenant in to aid Theramore. But no, the Kirin’tor leaders first had to agree to interfere, and then they had to agree to who to send.
If the expectation was that the Sunreavers were a wholly Horde aligned faction, and not a Kirin’tor faction, surely it would be dumb for both Rhonin an Aethas to recommend a Sunreaver agent with faction biases. But the expectation seem to have been, that the Kirin’tor is a neutral faction, and the Sunreavers and The Silver Covenant are a part of the neutral faction, therefor it is wholly expected that they do their duty as neutral factions, and not as Horde or Alliance aligned factions.
Hence why we often only ever see The Sunreavers and THe Silver Covenant (Disregarding MOP after The Purge of Dalaran) only ever participate in Kirin’tor sanctioned, neutral endeavours, Such as the war against the scourge and eventually the fight in Suramar, where it was also shown clearly that Vereesa was under the thumb of Khadgar and the Kirin’tor, and not Tyrande and the Night Elves, despite sharing camp.