When I was studying ML back in 2017 people were still calling things like image classifiers "AI".

We call things AI until they start working. See also: robots (your washing machine is a robot, but it works so you don’t think of it that way).

>> Cardiac events from Apple Watches is not “AI” though

> It would have been, 20 years ago.

No, it would have been called what it is both then and now; an asynchronous message emitted by a device having sensors capable of detecting when to do so.