Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/ReferenceHelper.php
public function updateNamedFormulas(Spreadsheet $spreadsheet, $oldName = '', $newName = '')
    {
        if ($oldName == '') {
            return;
        }

        foreach ($spreadsheet->getWorksheetIterator() as $sheet) {
            foreach ($sheet->getCoordinates(false) as $coordinate) {
                $cell = $sheet->getCell($coordinate);
                if (($cell !== null) && ($cell->getDataType() == DataType::TYPE_FORMULA)) {
                    $formula = $cell->getValue();
                    if (strpos($formula, $oldName) !== false) {
                        $formula = str_replace("'" . $oldName . "'!", "'" . $newName . "'!", $formula);
                        $formula = str_replace($oldName . '!', $newName . '!', $formula);
                        $cell->setValueExplicit($formula, DataType::TYPE_FORMULA);
                    }
                }
            }
        }
    }
public function updateNamedFormulas(Spreadsheet $spreadsheet, $oldName = '', $newName = '')
    {
        if ($oldName == '') {
            return;
        }

        foreach ($spreadsheet->getWorksheetIterator() as $sheet) {
            foreach ($sheet->getCoordinates(false) as $coordinate) {
                $cell = $sheet->getCell($coordinate);
                if (($cell !== null) && ($cell->getDataType() == DataType::TYPE_FORMULA)) {
                    $formula = $cell->getValue();
                    if (strpos($formula, $oldName) !== false) {
                        $formula = str_replace("'" . $oldName . "'!", "'" . $newName . "'!", $formula);
                        $formula = str_replace($oldName . '!', $newName . '!', $formula);
                        $cell->setValueExplicit($formula, DataType::TYPE_FORMULA);
                    }
                }
            }
        }
    }
Update named formulas (i.e. containing worksheet references / named ranges).

@param Spreadsheet $spreadsheet Object to update
@param string $oldName Old name (name to replace)
@param string $newName New name