I'm not talking about the special ones but the welcome amiibo ones like Plucky, Ketchup, Ellie, etc.?
Ever since I got the update about a week ago, I haven't had any camp site visitors. :/
None of the new villagers will turn up randomly, you have to buy the cards. Guess it makes sense really as nobody would buy the welcome amiibo packs if they could just keep time travelling to get them in game