I think the planning is not reflecting subsequent measures that are introduced by governments. For example, the departmental plans that are usually prepared early in the fiscal year or in advance of the budget don't include measures that are in the budget, so there is a time lag between the preparation of the plans and the implementation of these plans.
For example, in the budget, there are substantial resources for some departments and agencies: notably CRA, to improve response time for call centres, to take just one example. This will presumably require FTEs. The CRA departmental plan or agency plan probably did not reflect that. They may table plans that suggest a decrease in the number of FTEs, but what ends up happening, once they are made aware of the budget and the implication for each department and agency, is that it gets reflected in reality, and that very often leads to a revision upwards to the number of employees.