A French interview has confirmed what many of us suspected would be the case: cloud saves on the Switch will not be supported by New Horizons due to concerns of "manipulating time". Presumably they're referring to duplication issues, like giving an item to a friend and then re-loading from the cloud save or something. This could also be read as something to do with blocking time traveling, but I highly doubt that -- it's probably just a translation issue. (Japanese --> English --> French --> English possibly!)
Google Translate, but it's not a complex question so should be accurate enough:
https://www.gamekult.com/jeux/animal-crossing-switch-3050879505/test.html
They also dodged the amiibo question in terms of any details, but essentially implied they will be compatible somehow given how many there are.
Google Translate, but it's not a complex question so should be accurate enough:
With the advent of cloud saves and automatic backup, how will you handle Mr. Resetti's interventions?
HN : New Horizons will not be compatible with cloud backup , to avoid manipulating time, which remains one of the founding concepts of the series.
https://www.gamekult.com/jeux/animal-crossing-switch-3050879505/test.html
They also dodged the amiibo question in terms of any details, but essentially implied they will be compatible somehow given how many there are.