Psychonaut is describing how Gulliver works in wild world.
To OP, for accf, yes Gulliver should be there on the beach the following morning.
Possible reasons why not: another higher ranking special visitor might block him.
In which case you will have to wait till they go.
I don't think this is the reason tho, haven't got enough experience to say.
Are your gates open?
Go in and out of a building and look again along the beach.
This faq may help or may not.
http://www.animalcrossingcommunity.com/Topic/4781892/1/Gulliver_UFO_FAQ