This is a pretty common scenario. For example, Baldwin used to be a huge piano American manufacturer, and there are plenty of used American-made Baldwin uprights still around. They still make pianos, but as of 2008 they have outsourced all of their manufacturing to Asia.
Do those companies that outsource still do their own design? Apple outsources their production to Asia, but they are seen as an American company because they do their own designs. If the same is true for these piano companies I would argue they are still active American piano makers.
I think there's far too much skilled craftsmanship in a piano to call it American based on design alone. With Apple the company's DNA is the designers and programmers working in California. With Steinway and M&H it's the workers holding the chisels and hammers.
Astin-Weight seems to have quietly gone out of business, see for example their Yelp page:
https://www.yelp.com/biz/astin-weight-piano-mfg-salt-lake-ct...
Story and Clark now apparently outsources their manufacturing:
https://www.pianobuyer.com/story-clark
This is a pretty common scenario. For example, Baldwin used to be a huge piano American manufacturer, and there are plenty of used American-made Baldwin uprights still around. They still make pianos, but as of 2008 they have outsourced all of their manufacturing to Asia.
https://www.pianobuyer.com/baldwin
Companies like Steinway and Mason & Hamlin also have similar arrangements, but only for their lower-end pianos.