I'm really puzzled, why do you want to publicise your private medical diagnosis/diagnoses to your pupils' parents?
Would you be in such a rush to let them know you had arthritis, type 2 diabetes or any other medical condition you can think of?
It has absolutely nothing to do with anyone else except you, it's none of their business, alongside all of your other medical records.
If you need reasonable adjustments to be made at work, then by all means tell whoever it is in your school that would deal with those, but if not, there is absolutely no obligation for you to tell anyone at work.
I don't know if you've seen it but there was a fuss recently about the DVLA wanting anyone with autism to declare it, but that was soon rescinded and has reverted to its original basis of you only need to inform DVLA if your autism affects your ability to drive.
You are absolutely no different today then you were yesterday, your diagnosis is personal and if you keep it confidential like any other medical information, it will not affect your work, your ability to work nor how you are seen by colleagues, other staff, pupils, their parents or anyone else that knows you in a professional or friendship capacity. They will treat you as they always have done.
If you do decide to trumpet it from the rooftops to all and sundry, then do expect some negative reactions from some people, they will be the ones who don't understand what autism is, who "don't believe" in autism, who think autism is something you grow out of, who think particularly with high functioning autism that you could be just like them if you tried a bit harder, who think autism is a mental health issue, who think autism automatically means unable to work, who think you cannot be autistic because you can look them in the eye, who think we are all on the spectrum somewhere, who think ... well basically think of any misconception of autism and add it to this list.
There is a LOT of ignorance about autism outside the autistic community and their support networks, lots of the ignorance centres on education, have a look on the SN boards to see the struggles parents of neurodiverse kids have with getting schools to support them properly.
To answer your question, I wouldn't mind at all if my child's teacher was autistic because I have an autistic relative and am fairly much on the ball with how their autism presents etc.
However, I'd be very surprised indeed to be told by that teacher that they were autistic as I'd consider it to be absolutely none of my business.