It’s not at all likely that you’ll be audited, and it probably won’t cause problems with the return you submitted, other than a slight delay in processing. However, the IRS hasn’t provided guidance on this yet.
It's possible, if not likely, that the IRS will make the correction during processing, based on its own stimulus records, and adjust your refund accordingly (that is, lower it by the relevant amount). If that's the case, the IRS will send you a notice telling you they've made the correction.
Please see the IRS Recovery Rebate Credit page for more details as they develop.