Trader Joe's is a bad example, they are notorious for discontinuing items that never return to shelves. This behavior is referenced in this old viral video https://www.youtube.com/watch?v=OdB7GDZY3Pk
They discontinue plenty of things, but the employees are more helpful and more informed than the Amazon example.
Interesting, at my Trader Joe’s they always ask, and when I do say I couldn’t find something they just shrug and apologize. Ironically this is the TJ’s up the hill from the new Go store mentioned.