The preparation of sustainability reports, which a negligible number of organisations had been doing until recently, will soon be the new reality for many more organisations. This research aims to present changes during the COVID-19 pandemic in the ecosystem of sustainability reporting pronouncements, especially those used by organisations. In our research, we compare important information about two different periods and the content demands in reporting on sustainability. Changes in the ecosystem are fundamental and unique. Based on the analysis of events and documents, the current research shows the changes in the ecosystem and the future dynamics in the ecosystem, including the principle standard setters (i.e., International Sustainability Standards Board and European Financial Reporting Advisory Group, EFRAG). The research shows that although the changes occurred during the COVID-19 pandemic, they did not significantly impact the ecosystem’s development or slow down or stop their development. The COVID-19 pandemic did not affect the speed or dynamics of changes. In the last few years, EFRAG and the European Union established their position and gained a significant influence in sustainability reporting, with EFRAG at the forefront. The European Sustainability Reporting Standards will be mandatory for organisations doing business in the European Union. At the same time, we do not expect that the IFRS Sustainability Disclosure Standards will be directly endorsed for use in the European Union. The paper presents a new perspective on examining sustainability via developing organisations’ reporting demands within the framework of the uncertain environment caused by COVID-19. In this context, our research also contributes to the literature. The study also has a potential practical impact on organisations and management since it illuminates a wide range of selected sustainability viewpoints and their reporting.