I see a contradiction, here. Gay people wish to be normalized and I happen to think they should. Requiring books to state that Sally Ride was a lesbian does the opposite. Since her lesbianism has nothing to with her work, that strikes me as tantamount to demanding that textbooks teach that somebody was left handed.
It draws attention to something that doesn't matter.
While I support gay rights, I do see an agenda at work here and I do not believe young children should be treated like lab rats. These issues should be reserved for at least middle school if not high school.
I do not see any contradiction at all. The point, in this case is that Lesbianism is normal. It demonstrates that a Lesbian is just as capable as anyone else. As for left handed people, 60 years ago or so, being left handed was considered abnormal and they tried to make left handed kids into right handed kids. In those days if they were learning about a great painter or musician who was left handed, it would have been appropriate to mention it also.