> EDIT: Alternatively, and more innocently, this could be due to the end of the life-cycle of several appliances in Second/Third World countries -- or maybe even First World (do you know anyone with an aging fridge?). While a lot of people might have done away with their old fridges a long while ago, those that didn't might be seeing them all fail nearly at the same time.
The original paper takes a stance on this.[1]
> It seems unlikely that the increased CFC-11 emissions are related to faster releases from banks or from inadvertent production. Increases in bank-related emissions are thought possible from the demolition of buildings that contain CFC products, although these emissions are expected to be small and only slowly increase over time 22 . Furthermore, an increase in CFC emissions resulting from the decommissioning of buildings is anticipated to occur initially in developed countries in which most CFC-11 was used in the 1970s. However, atmospheric measurements suggest, for example, a decline in US emissions from 2008 to 2014, which is consistent with inventories 23 (a qualitative update suggests no substantial increases in emission after 2014). If reported production values are accurate, our results would require a doubling in the fractional release rate from CFC banks over the past 15 years and a substantial increase in emissions from banks since 2012, both of which seem improbable (Fig. 2b; Extended Data Fig. 9)
> ... These considerations suggest that the increased CFC-11 emissions arise from new production not reported to UNEP’s Ozone Secretariat, which is inconsistent with the agreed phase-out of CFC production in the Montreal Protocol by 2010.
[1] https://www.nature.com/articles/s41586-018-0106-2