Steve Burley, who appeared on MAFS season seven, was one of the first stars from the Nine Network program to wish the couple well.
"So Happy for you both," he commented on a photo of Melissa and Bryce holding their babies' ultrasound.
"Congrats guys on keeping the red race alive. #redheads," season four MAFS star Nick Furphy wrote.
Jessica Brody, whose tumultuous romance with Ciarran Stott played out on Bachelor In Paradise, said she was "so happy" for the parents-to-be.
Kerry Knight, one of Bryce and Melissa's few friends from their season, also congratulated the couple publicly.
"Incredible news you guys!! Huge congratulations!!!!!!! Twins!!!!! I can’t believe it!!!! ❤️❤️❤️❤️❤️ Sending so much love to you both xx," Kerry wrote.
Bachelor In Paradise alumni Bill Goldsmith commented: "Your kidding! Congratulations" while MAFS season eight star Jason Engler also showed his support, writing, "Who would have thought after going to hell and back this would be the outcome!!Congrats. Love ya’s".
But not every reality star was as thrilled with the couple's announcement, particularly former Bachelorette Georgia Love.
Responding to Bryce Ruthven and Melissa Rawson's exclusive spread in New Idea, the 32-year-old posted a close-up image of Bryce with the caption: "Siri, show me the face of "I've taken it too far"."
A MAFS fan took the opportunity to take a cheeky swipe at Bryce over his previous comments about only being attracted to women with blue eyes.
"What if the babies don’t have blue eyes but," the woman wrote.
The pair say they’re planning a “low-key” wedding – nothing like their TV nuptials. And while Mel has big plans for the day, their focus is now on their family.
“I’ll have two babies by the time I walk down the aisle,” says Mel, nervously.
The show's most polarising couple previously admitted to New Idea that their portrayal on TV’s toughest social experiment left them “broken”.
Melissa bravely confesses that the show left her feeling “not suicidal, but headed down that path”, while Bryce says he felt “utterly helpless” after the couple were manipulated into staying on the series.
The persistent scandals that plagued their time on the controversial series quickly saw Bryce become one of the country’s most contentious TV grooms and Melissa, his “victim” – an image they say is so far from the truth that “it’s laughable”.
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