The War for Wakanda update to Marvel's Avengers seems to be making references to several upcoming characters, such as Loki, Scarlet Witch, and Doctor Strange.
One player, FWM_Carlton, ran into the discovery whilst exploring Wakanda with Thor. In the clip, which was posted on Twitter by PlayAvenger, Thor is seen running into a room to talk to Zawavari. After doing so, Zawavari is heard saying, "Well, this is a pleasant surprise, Wanda".
Related: Spider-Man Is Still "On Track" To Come To Marvel's Avengers In 2021
Players originally believed that this was a glitch and that Zawavari was reacting to Thor entering the room as if it was Wanda, believing that the game had got mixed up on which character the player was controlling. On further inspection though, it seems like Zawavari is actually speaking to Wanda through a portal.
Sticking around to listen to Zawavari for more time also has him referencing Pietro, Loki, Doctor Strange, Wong, and Daniel Drumm. At the very least, it's confirming that all of these characters exist in this universe, but it also seems to be hinting at some playable heroes who could be added to the game, such as Doctor Strange, Loki, and Scarlet Witch.
Some players have also reported having Zavawari reference Spider-Man during his conversation, although there aren't any videos of the exchange online. If this was true it would seemingly add more credence to the idea that this is one big tease for characters, as we know that Spider-Man will be making his way to the game at some point.
When Marvel's Avengers first released, code within the game was datamined which revealed a list of characters that could be coming to the game. Although plans have likely changed since then, some of the names mentioned within the game's files including Captain Marvel, War-Machine, She-Hulk, and The Winter Soldier, none of which are mentioned in War for Wakanda.
Those characters all had some code attributed with them, but Doctor Strange and Scarlet Witch have previously been hinted at in the game, just without much work having been done on them. At the very least, this could be an indication that we'll see these characters within this world at some point.