In-game shorthand can tell you a lot about new content even when you don't quite know yet what all the acronyms stand for.
For example, when we first started questing in Avernus, we quickly noticed that chat was full of "+siege" and "+ape". This indicated that there were at least two big heroic encounters (BHEs, or "beehees" as my husband likes to call them) on the map that people liked to run for the rewards.
"Ape" seemed like a bit of an odd name, mind you, but we soon found out that this was because while the encounter was technically called "Demonic Summoning", it involved killing a giant Barlgura, a type of demon that looks like - you guessed it - some kind of ape. Why waste precious syllables when a simple "ape" will do it?