You can find this information in 1026.19(e)(3)(iv)(D) that states that a creditor may use a revised estimate of a charge instead of the original LE if the points or lender credits change because the interest rate was not locked when the Loan Estimate was provided.
No later than 3 business days after the date the interest rate is locked, the creditor shall provide a revised LE to the consumer with the revised interest rate, the points, lender credits, and any other interest rate dependent charges and terms.
When originally released, the regulation would’ve required the revised LE to go out the same day, then a “proposal” was issued to change that requirement to “no later than the next business day after the date the rate is locked”; however, the final regulation states “no later than three business days after the date a rate lock agreement is entered into.