"This is our fifth statement, published in accordance with the Modern Slavery Act 2015, setting out the steps we’ve taken during year ending 31 December 2020 to prevent modern slavery in our business and supply chains".

Note: the fact that they mention this is their fifth statement that has been published in accordance to the Act, I assume they are "Developing a new modern slavery policy".

Although the statement says this is their fifth statement, it doesn't necessarily describe any changes in their policy due to the UK Modern Slavery Act 2015. It could have been a stronger statement if the company added what changes they've made from the previous statements.