The DC FanDome guest lineup has been announced and the majority of the Supergirl cast including Melissa will be participating.
https://decider.com/2021/10/04/dc-fandome-full-talent-list-2021/
https://screenrant.com/dc-fandome-2021-guests-jason-momoa-dwayne-johnson/
Two more huge swaths of actors appearing are likely to be part of panels. The first is from the upcoming HBO Max series Peacemaker, with John Cena (Peacemaker), Freddie Stroma (Vigilante), Steve Agee (John Economos), Danielle Brooks (Leota Adebayo), Jennifer Holland (Emilia Harcourt), and Chukwudi Iwuji (Clemson Murn) appearing. The second is from Supergirl, which will air its series finale later this year. Appearances will include Melissa Benoist (Supergirl), Chyler Leigh (Alex Danvers), David Harewood (Martian Manhunter), Azie Tesfai (Kelly Olsen), Mehcad Brooks (Guardian), Chris Wood (Mon-El), Jesse Rath (Brainiac-5), Julie Gonzalo (Andrea Rojas), Katie McGrath (Lena Luthor), Nicole Maines (Dreamer), Peta Sergeant (Nxylgsptinz), and Staz Nair (William Dey).
Major step up from last year when there was nothing for Supergirl.
Also,reminder,Melissa has a panel at NYCC this week promoting her new book and Supergirl.
https://www.newyorkcomiccon.com/en-us/explore/panels/panel-information.html?gtID=748623&panel-name=Melissa-Benoist-and-amp-Thomas-Lennon-Supergirl-Costars-and-Authors
Melissa Benoist & Thomas Lennon: Supergirl Costars and Authors
Thu, Oct 7, 2021
10:00 AM
Virtual Only Programming
Join actors Melissa Benoist and Thomas Lennon as they reveal the inside scoop on all things Supergirl and their journey from costars to authors of new middle grade novels. Benoist is publishing The Powers: Haven’s Secret with her sister Jessica Benoist on October 19 and Lennon will publish the third book in his Ronan Boyle series Ronan Boyle Into the Strangeplace in November.
ETA
Here the guest announcement trailer.
https://www.youtube.com/watch?v=wdE-GwHWd8c
Also Canadagraph's has blog up for the,"Armageddon" shooting from the other day.
Massive spoilers there but if you want to see photos of Chyler filming The Flash event,you can check them out there.
https://twitter.com/canadagraphs/status/1445022572312084481
https://canadagraphs.weebly.com/the-flash-blog/the-flash-armageddon-set-photos-with-massive-spoilers