This seems like really quite bad design.
EDIT: 1) is the result of my misreading of the article, the "previous value" never existed in git.
1) Pushing a change that silently break by reinterpreting a previous configuration value (1=true) as a different value (1=0.100ms confirmation delay) should pretty much always be avoided. Obviously you'd want to clear old values if they existed (maybe this did happen? it's unclear to me), but you also probably want to rename the configuration label..
2) Having `help.autocorrect`'s configuration argument be a time, measured in a non-standard (for most users) unit, is just plainly bad. Give me a boolean to enable, and a decimal to control the confirmation time.