Procrastinator it's a first instance decision and therefore not binding, but even so, it doesn't tell us much. The Tribunal accepted that the Claimant had told her employers she was intending to undergo gender reassignment as far back as 2017 - bringing her from that moment within the scope of s.7 Equality Act which defines gender reassignment as undergoing, proposing to undergo, and having undergone gender reassignment. That must be right: if someone announced an intention to transition and was bullied in the workplace and left soon after, the employer could not say "well, they didn't have time to transition as they were bullied out for announcing an intention to do so, therefore they are not protected."
The Claimant said, and the Tribunal accepted, that in March 2017 she had told her employer that she intended to transition, and that she was transitioning from male to female (para 19). She later in April and May described her current state as "gender fluid" but there is no suggestion she had renounced her stated intention to transition to female (and indeed she gave evidence to WESC describing herself as a trans woman). In June HR were describing her as transitioning and using 'she' pronouns.
The employer's paper-thin defence until mid proceedings was that the Claimant hadn't named the people who were bullying her and therefore they couldn't possibly be expected to deal with it.
It was only after proceedings began, at a case management hearing, that the employer - one hypothesises, shitting themselves and grasping for straws - noticed the words 'gender fluid' and tried to argue that if the claimant was gender fluid then she didn't count as trans for the purposes of the Equality Act.
That was absolutely doomed. Her stated intention to transition from March 2017 brought her within the s.7 definition whether or not she had ever followed it through.
However, it doesn't follow that a person who had not stated an intention to undergo gender reassignment but simply "identified" as non binary would be covered. It would be fact specific and would be up to the tribunal to make findings as to whether they were covered, depending on what they had said. "I identify as non binary" is unlikely to attract protection, whereas "I am undergoing a process of transition and currently view myself as non binary" quite possibly would.