Given that the semi-parliamentary nature of the Brazilian political system was aggravated by the political vacuum left by the Bolsonaro administration, cabinet shakeups to accommodate indications made by some Centrão leaders are vital to the government's governability. There's no other way to consolidate a permanent majority for the government in Congress on key issues.
This unlikely alliance comes as Lula has faced trouble in advancing his program through the fragmented, right-leaning legislature, suffering several defeats despite progress on loosening limits on public spending and approving a tax reform. Yet, these cabinet posts will not ensure unconditional nor durable support to his government, especially in the face of more radical proposals.