Wiktionary wrote:
yay
(colloquial) yes
An expression of happiness
"Yay! I have finally finished my work."
So sayeth the Wiktionary. "Yay!" is therefore not an expression of pride. I can well imagine your happiness at getting officially labelled - if I may use the popular "square peg in a round hole" analogy of AS, you are now a legally-designated square peg, which ought to come in handy when people who should know better are about to hammer you into their agenda. Its use is probably somewhat limited, but given the level of cynical disbelief I've read about from self-diagnosed Aspies, I'd feel somewhat safer with that official label.
I think it might also simplify things for anybody who feels the need to know about themselves. I feel strongly that self-knowledge is invaluable for the effective pursuit of happiness/fulfilment in life, and now you have a pretty clear perspective on your condition, you've taken a good step towards that. Certainly for me it's a source of frustrating complication to always have to think "if I'm an Aspie then that explains it, but if not, well it could be this, it could be that...." If you strongly suspected you were AS before, the experts have concurred with your diagnosis - you were right (if not, I suppose you'd be feeling somewhat crestfallen rather than jubilant).
You may also find it easier to be understanding about times in your life when people have been inexplicably impatient with you (if there have been any) - it's not always their fault, if nobody knows you have a brain-wiring difference then people will jump to the first plausible explanation for any strange or awkward behaviour, unless they're on an unusually high plane of enlightenment. I haven't noticed many employers or officials in that category.
So, well done