The Hannah Ashworth star exited the Channel 4 show late last year. Since producer Paul Marquess took over, Sonny Flood, Suzanne Hall and Jim Millea have all been written out of the programme.
Rigby, who attended their leaving party, told PA: "I'm sad it's coming to an end. I think they were quite emotional when they left. I don't think they were quite ready to go.
"But I suppose they'll all be doing new things."
The 20-year-old also revealed that she didn't know some of the the new faces at the event.
"I've not watched Hollyoaks for a while because I haven't had time but I believe there's loads of new people," she said. "When I went to the leaving party I didn't recognise everybody."