Well, that's troubling. I hope the cast and crew remain safe .The Flash temporarily shuts down production on season 7 due to an infection ‘The Flash’ Pauses Production After Positive Covid-19 Test
7x1 - Nash trying to figure out how to give Barry his powers back ?
I'd kind of assume Captain Cold so we can get a Rogues episode, but I'm not sure if Wentworth Miller would be willing to do it, but I guess they could bring back one of the dead Speedster villains like Zoom...At CCXP this past weekend, Danielle Nicolet (Cecile) teased some fan favorite villains will return in season 7 after more or less confirming time travel will still be a component of the show.
The official character description tells us, “Scientist Mark Stevens is a charismatic bad boy obsessed with cryogenic technology. But when he’s not breaking into corporate safes, he’s busy breaking hearts with his irresistible charm and roguish style. Armed with his own cold weapons, he’ll become a new thorn in the side of Team Flash as the DC Comics villain Chillblaine.”