School meals never have been provided over the summer holiday, indeed any holiday.
The voucher scheme, which was introduced very quickly as a result of the coronavirus crisis was designed to help parents provide a meal (for children eligible for free school meals) when a school had decided it could not provide meals as normal, whether to children attending the school or for those not allowed to attend.
The government set up a summer holiday club initiative in 2018 for children eligible for free school meals. This was enhanced in 2019 and supported again this year. Furthermore, recognising the emergency situation we are enduring, the government is giving £63M to local councils for welfare assistance, specifically regarding food and other essentials. More detail here - https://www.gov.uk/government/news/63-million-for-local-authorities-to-assist-those-struggling-to-afford-food-and-other-essentials