The 61-year-old was forced to miss the BGT finals after he broke part of his back while testing an electric bike at his house in Malibu.
In Cowell’s absence, Holden, 49, became BGT’s head judge and Ashley Banjo joined the panel.
Today, she told Good Morning Britain that Cowell’s partner “Lauren [Silverman] is always saying to me that, ‘His will to get better is extraordinary.’
“He’s very determined. He’s a fighter… There’s no way he will want to be seen to be failing or to not be getting better as quickly as he possibly can.
“So, I know that we will see him next year.”
Holden joked that having to fill in for Cowell that she was “going to ask for parity of pay. I think that’s only fair.”
“As a female and as the head, I should be at least on the same wage as him,” she added. “And then I could donate it and save some theatres.”
Piano player and funnyman Jon Courtenay won the latest series of the ITV show, winning by a landslide.
“I was totally thrilled for him. He said he was down to his last £500 in the bank so that money is going to be life-changing for him,” Holden said.
It was an emotional final for Courtenay, who fell to his knees upon hearing the news he’d won BGT’s grand prize – £250,000 cash and a slot performing at the Royal Variety.
“I tried not to think about it because I am really bad at hiding disappointment,” he said. “This morning for the first time, this sounds really dramatic and I literally, woke up with an idea for a song for the Royal Variety Performance.
“I wrote it down and I tried not to think about it as being a sign because as I say it would be too much pressure.”
Saturday night marked the end of Britain’s Got Talent this year, with the most recent series having been marred by controversy and Ofcom complaints.
Over 20,000 viewers took to the broadcasting watchdog over former BGT winners Diversity performing a powerful routine which paid homage to the ongoing Black Lives Matter movement.
Additional reporting from PA