Yes, it is the case. From The National Agreement ;
7. Classification Options and Reviews
a. Any rural carrier whose route may be classified
in more than one evaluated classification may
elect the higher route classification if the following
requirements are met:
(1) It must be demonstrated that the rural
carrier’s actual work hours will not
exceed 2,080 during the guarantee period.
Christmas overtime hours, if any, will
increase this benchmark, provided that
the hours in excess of 2,080 occur in the
last pay period of the guarantee period.
Such determination should be based on,
but not limited to, the rural carrier’s performance
during the previous year;
(2) The rural carrier agrees in writing to use
sufficient annual leave to assure that the
total actual hours worked, with appropriate
consideration of Christmas overtime,
will not exceed the 2,080 annual guarantee;
and
(3) The rural carrier must have a minimum of
ten (10) years from the retirement computation
date.