Yeah to be blunt Chrome are violating:
https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#autofill
Which specifies in black-and-white-and-red-and-blue:
When wearing the autofill expectation mantle, the
autocompleteattribute, if specified, must have a value that is an ordered set of space-separated tokens consisting of either a single token that is an ASCII case-insensitive match for the string "off", or a single token that is an ASCII case-insensitive match for the string "on", or autofill detail tokens.
The reasoning by Google is that they no longer trust developers with off so they ignore it. This is user hostile, standards hostile, and the list goes on.
If other browsers (aka. Firefox) stumble with autocomplete="discourse" I will revert this so the community can take it up with Chrome.