Lauda is "he" and anyone thinking otherwise is just fooling themselves. I guess people like to think that Lauda was "she" as we lack females in crypto and he was amused by people guessing his gender. After all, there is an old rule that says that on the Internet everyone is male until proven otherwise.
Gonna quote one of my previous posts why I have no doubts about Lauda's gender and I think that pretty much goes for everyone else that understands Croatian.
It is unknown whether Lauda is male or female, or what age Lauda was. I say “she”, because I think that Lauda had feminine behaviour. But she refused to disclose all such information, for reason of privacy. I myself asked her many personal questions. All that she would say was, “I’m a cat.”
All those that understand Croatian/Serbian shouldn't have any doubt whether Lauda is a male or female. Among other things, we have genders for verbs in past tense and adjectives. In his posts made in Croatian board, Lauda always used masculine gender. I remember some time ago I was so bored that I actually tried to find posts where he used feminine gender, to no avail.
Just an example from one of his posts. Adjectives and verbs are bolded, all masculine gender.
Razumio sam sada.
Ne bih
rekao ali u svakom slucaju ne bih ti
preporucio.
Da nisam
procitao ovu temu ne bih ni
skontao .
Zauzet sam nesto trenutno, ali bar ima srece s ovom cijenom.

This is how it would look like if it was written using feminine gender
Razumila/Razumjela sam sada.
Ne bih
rekla ali u svakom slucaju ne bih ti
preporucila.
Da nisam
procitala ovu temu ne bih ni
skontala .
Zauzeta sam nesto trenutno, ali bar ima srece s ovom cijenom.

Maybe Lauda wanted to hide his gender right from the beginning, but somehow I think that he had just a bit of fun with people guessing it because of his name ends with an "a" or whatever else started all that, even though when I heard his name for the first time it didn't sound as a female name since it reminded me of a famous Austrian F1 driver Niki Lauda.