No one gets the loan until their return is accepted, and the IRS starts to accept on Jan. 27.

https://ttlc.intuit.com/questions/2938482-how-do-i-take-a-picture-of-my-w-2-in-turbotax-online

I understand that. I am just wondering if those that claim child credits will have to wait longer for the advance since the irs won't begin processing those until mid February. 

It is not that the IRS will not start processing returns with the additional child tax credit; it is that they will not issue refunds before mid-February if you are getting EIC or additional child credit. Not the same thing.  Even if they have processed your return they hold the refund.

The loan information does not make any reference to holding the loans if you are getting child credits.

So be on the lookout after Jan. 27 when your return could be accepted.  The loan could be released shortly after that.

Thank you!