The 74-year-old – who was on the judging panel of the dancing competition for five series – was given the boot from the show in 2008 and was replaced by former contestant Alesha Dixon.
The shock move resulted in viewers accusing the BBC of “ageism” and Arlene has now revealed she was never “given a real reason” as to why she was axed.
“I’ve never really been given a real reason [as to why I was axed]. I don’t think I will ever know the answer. Certainly after Strictly I was in a very vulnerable situation,” she told Good Housekeeping.
The choreographer continued: “Prior to finding out that I was not going to be on the panel I had lost my manager of 30 years to cancer. I couldn’t think about fighting, I couldn’t think about losing a job. I was in despair and grief-stricken.
“I didn’t stand up or make my voice heard. I wasn’t in a place to be able to do that. But I have a 48-hour rule – it’s what I tell dancers and it’s what I tell my children – give yourself 48 hours to moan and groan, then just get up and get on with it.”
Arlene also opened up about the prejudice she experienced when she became an older mother after having her second child aged 47.
=“[I was told] I was some kind of freak, that I would find it hard to bond with my baby when I could be the grandmother. I’m so vociferous if anybody says something to me that I find offensive. But I was so vulnerable. I let all these remarks go by with tears in my eyes.
“Nowadays, being an older mother is very common. When you let all those things go you see the absolute joy of having a baby when you’re older. You really do feel like you’ve been given a gift.”
Earlier this month, Arlene appeared to back Strictly’s decision of hiring Shirley Ballas to replace head judge Len Goodman.
Speaking on Good Morning Britain, the original member of the judging panel called the 56-year-old “fierce and tough”.