I'm forced to disagree. Legion wasn't considered a cosmic expansion because it took place on Azeroth. A Lightbound invasion would also take place on Azeroth, so similarly I wouldn't consider that a cosmic expansion either. "Cosmic expansions" are when we leave Azeroth, such as TBC, WoD, and SL.
+Yrel appearing in BFA as the head of an antagonistic army.
+
Avatar popping up on BNET among Shadowlands characters for no reason
+10.1.5 Fractures of time showing the different possible futures and timelines of AU Azeroths is a possible hint of AU Draenor (which is supposedly dying because of it being linked to MU Azeroth in the time stream).
+Thrall on the promo art for BlizzCon 2023. The Lightbound invasion would be a Draenei and Orc focused expansion.
+The next expansion will fall on the 10th anniversary of WoD which was a celebratory expansion partially designed to celebrate the 10th anniversary of Wow in 2014.
Let me stress, I'm not saying that a Yrel expansion is for sure going to occur, but based on the evidence, it seems like a very likely candidate. Especially when you consider that it can be used for both a revamp as well as bringing in two sought after playable races: Arakkoas and Ogres.