It seems that a court has ordered Amazon to deliver only essential products [0], and Amazon's reaction is to suspend all deliveries.
They write in their other tweets [1] that the decision is based on (i) the fine of €1M per infraction imposed by the court, and (ii) the risk of contravening the decision being high due to complex logistics.
[0] https://www.bbc.com/news/world-europe-52285301 [1] https://twitter.com/AmazonNewsFR/status/1250481151313154048