Board Thread:Questions and Answers/@comment-27766744-20160525044527/@comment-16461120-20160531085304

Zarda was the only Squadron Supreme survivor actually in Earth-15513 for Secret Wars. She was last seen in Doomstadt on Battleworld, so it's reasonable to speculate she may have been "rescued" by Reed Richards during the final battle. We know Roberta Mendez said she was rescued by Reed, so others likely were as well.

Marc, Nemet, and Thundra were all already in Earth-616 prior to Last Days.

Raymond allegedly died off-panel during Time Runs Out, but since we know Nemet was saved from the destruction of her Earth, it's possible she wasn't the only one rescued in that manner.

And that leaves Jeff, who is anybody's guess, 'cause he hadn't appeared in the past decade in anything so Gods only know where he's been between then and now.