If you have never done this before, let me suggest that if you like the culture it currently has, you need to be really leery of making significant changes, such as deciding you will welcome men at some point after starting out as exclusively female.
I have been a member of predominantly female groups. If there is a single man in them, they fail to be some kind of female empowerment zone. He will have the largest influence any time he posts and he will be backed by vicious female allies who will have a huge problem with any woman standing up to him. It is bizarre stuff.
The one group I briefly belonged to that was initially exclusively female due to happenstance promptly crashed and burned when the first man joined. After ugly stuff went down, the list basically died. It was eventually disbanded, even though he quickly left because of the drama. The group never recovered from the debacle.
This theory is notoriously used by the military in many nations. By strengthening the in-group feeling you gain several traits such as increased confidence and feeling of belonging, and you increase tensions against the out-group which during a war is perceived as useful.
Benefits and drawbacks, one which many nations has gone with banning the practice of single sex education. I don't disagree with it and I find the science behind it to be rather robust.
Women have a tendency to be too empathetic and understanding and society tends to hang a lot of expectations on them to be so. If women want careers, being a little less caring and a little more goal oriented seems like a constructive outcome to me.
Where is the research on that?