I think that was a good decision, I find that people tend to sometimes get overwhelmed if you mention the transition early in because they don't know you and then they struggle to find ways to relate to you in light on this new information. It sucks but sometimes when someone's first impression of you is "the transgender person" they forget that you're an actual person with other aspects to who you are. I think that if, in the time where you stay in the closet, you develop a good reputation at the job, your coming out will be a non-issue.