It's a risk. Sometimes disclosing after being hired turns out well and sometimes it doesn't. You're putting trust in the people you disclose to. I would say that disclosing is only a good idea if you are confident that you cannot pass or explain quirks in any other way OR if you strongly feel you need to further the cause of autism awareness. Like out and proud.
You can always ask for informal accommodations without disclosing anything personal. "The lights bother me, can we open the blinds instead?" "I need things to be explained bluntly, if you don't mind." "I didn't get the point of that meeting, could you explain the gist of it to me?" Those are ways that aspies and auties will ask for help without getting into any discussions of autism. No one thinks anything of it and will help you out. They will ask you for help with something else later. Maybe they don't understand a diagram, or would like you to please stop tapping your foot. Just simple kindness can work as well as accommodations.
As to the other point- is being autistic an advantage? Of course it is. Any person who is putting together a team wants a diverse team. You want mostly a certain kind of person, then a few outliers that are unique kinds of people. Different thinkers. Often these people will rise to be leaders and information specialists. But if the people who are hiring are not autism savvy, don't drop the A-bomb. Most people are not going to respond if you say, by the way, I'm on the spectrum, and then wink knowingly. There's no, like, card you can hand them to tell them what that means.