I don't think it is associated with rape.. from my experience of the use of this word in western women centred activities, it relates to a space where women come to share and talk, around the physiological and emotional aspects of life that are unique to womanhood, reflecting the spaces that were reserved for women in pre modern times, during menstruation or birth most often associated with impurity . I can only find reference to the book by of that name by Anita Diamant written in 1997 and I don't know if such a space is traditionally referred to as a 'Red Tent'.
Anita Diamant herself writes: "when I hear women wax nostalgic for a monthly time-out, I feel obliged to reply that my account has nothing to do with the facts about menstrual sequestration, which for the most part has been, and remains, cruel and dangerous" and "where there used to be huts and foxholes where women were sent to suffer, we’ll build a clubhouse where sisters and friends go to relax and learn, and where mothers can tell stories about the bad old days to their unbelieving daughters."
For many women, this practice remains one of oppression rather than liberation.
(Not sure I am adding to this conversation, but I have been thinking about it.. )