The author of that article wrote, "If you absolutely need the CLI interface, I do not really have any good recommendations for you." I think the existence of the (minor[1]) issues raised in that article are less annoying than having to use a GUI password manager (but I'm generally anti-GUI).
PGP has a kind of authentication called MDC which is kind of a MAC. Changes to ciphertext are detected.
The metadata leakage is not good from a privacy standpoint, but brings about much more important security benefits that are mentioned in the post. Using Gopass will hide metadata.
This is very much a case of "don't invent your own cryptosystem", especially not in bash.