As in, the workers who they hope will come back because of free childcare.
I don't know many mums that don't go back to work straight away.
The few I have met feel strongly about being at home and I don't think free hours would change that.
The ones (two) I have met who left jobs and would like to return but can't afford childcare are in healthcare and hospitality where regular shifts don't fit in with nursery opening times anyway.
Tbh and only in my opinion, a lot of the 'we can't afford childcare so I had to give up my job' crew are often told that by controlling DH/ DPs or don't really want to go back to work anyway. Happy to be proved wrong!