I don't necessarily think that is the case. Though there are exceptions like City Folk and New Horizons, a good chunk of the Animal Crossing games released just about a year after the system they were for released. In New Horizons case, it took a while because the same team was working on Splatoon 2, but it's been rumored that EPD 5 has expanded to the point where they can more easily work on both simultaneously.
I think we could potentially see Animal Crossing fairly early in the system's life, especially as a new Smash Bros. looks to be far off, and Nintendo will want to prioritize new entries of their major properties on Switch 2.