The Foundation sees this as a contradiction to the EU’s own interoperability goals. Although XLSX is standardized as OOXML according to ISO/IEC 29500, Microsoft’s implementations often deviate from the specifications. Furthermore, features often change undocumented, which complicates compatibility with open-source software such as LibreOffice.
Yes, it would probably force microsoft to adhere to the specs if their files didn’t work more users.
or you know you could require them to comply
The right wing is in charge of the EU now – they’re not going to require companies to do anything