

Yes, it is used consistently in GNU Coreutils
: https://www.gnu.org/software/coreutils/manual/coreutils.html#Conditions
-
false: do nothing, unsuccessfully
(returns 1) -
true: do nothing, successfully
(returns 0) -
test: check file types and compare values
is documented as “returns a status of 0 (true) or 1 (false)”
I can sorta see that. An exit code is an exit code. But exit codes, like words, have meanings. Sometimes that meaning is a boolean value, as is the case in e.g. GNU Coreutils conditions: https://www.gnu.org/software/coreutils/manual/coreutils.html#Conditions