are there plans to add a gender select in the future?
I don't think so. While an interesting idea, I don't see a lot of specific conversations happening if the MC is a female. I am not sexist, but I really don't see Alex saying, "What your dick does to me is special" or a lot of moments where "cum inside/creampie" to get a pregnancy apply to a female-female situation.
Mr evil is correct, there are no plans to add the option for a female protagonist. While none of the actual relationships and vast majority of the text would change... the sheer effort in redoing the thousands of renders and hundreds of videos makes it untenable, not to mention coming through the entire game for tens of thousands of lines of gendered dialogue.
And Nunu is correct. It would literally be doubling everything. The number of interactions with the mc, the number of dialogs, as well as even the size of the game. Working to add even one simple thing can mean a decent amount of work. In the case of gender addition, it would be like making a CBTL sequel.