They had had below-replacement fertility and depopulated rural areas for decades. There is plenty of room for more children now.

Their top priority should be increasing overall fertility back to 2.1 on average, with focus incentives on locals of rural areas making more kids ( with care not to displace the actual locals with urbans with no roots there just moving a few years to have their kids there and then leave ).

Even if they got their fertility index back to 2.1 right now, their population would gradually decline by several millions untill it stabilizes.

They should aim that 2.1 is the minimum and 2.5 a much-needed catching-up for 2 generations.