Chris Pratt, Dave Bautista and Tessa Thompson are currently doing their COVID quarantine after arrival in Australia to shoot Thor: Love And Thunder. Idris Elba and Doctor Strange’s Tilda Swinton are also already in Australia due to other projects and are rumored to be involved in some way.
Now the Daily Telegraph reports that Matt Damon has arrived with his entire family on a private jet and will quarantine for two weeks before heading to the set.

Damon had a small cameo as an actor playing Loki in a stage play in Asgard in the previous movie Thor: Ragnarok. Would a 15 hour flight by private jet and a two week quarantine really be on the cards for another two minute cameo?
Of course, Matt Damon has form for Marvel cameos. Another little known appearance is his turn as a redneck in Deadpool 2.

Damon is a long-time friend of Chris Hemsworth and has previously spent a long vacation in Byron Bay near Hemsworth’s sprawling property. Maybe they are just combining a long family vacation with a fun cameo, with the added advantage of being away from LA for a while right now?