No... it says they WILL work under the provisions...
ARTICLE 1-PROBATIONARY
EMPLOYEES-SEASONAL EMPLOYEES
Section 1
(a) Probationary employees: a new employee shall work under the
provisions of this Agreement but shall be employed only on a thirty
(30) working day trial basis, during which period he/she may be
discharged without further recourse; provided however, that the
Employer may not discharge or discipline for the purpose of evading
this Agreement or discriminating against union members. After
working thirty (30) days within a ninety (90) consecutive day period,
the employee shall be placed on the regular seniority list, and
his/her seniority date shall revert back to the first (1st) day of the
thirty (30) day period in which the employee gained seniority.