I don’t exactly agree about the shadchan, but it kind of depends on your community’s style of dating.
It seems to me that by the time you are thinking of getting married, the shadchan’s role is no longer to be a go-between, but just to give sage advice to either and both of you. It seems funny to me that you’d be thinking of getting married if you aren’t comfortable telling him that you are thinking of getting married.
But again, it depends on your community’s style. If you are a 5-6 date community, and it isn’t really expected that you’ll have much of a relationship before getting engaged, then perhaps the shadchan would still have a go-between role.