Windows Mobile has not had the ability to handle OOXML-based documents until now.
This might make 2 applications which are built from the same codebase and properly support a derivate of OOXML. Both applications come from the same company, to whom OOXML is "a simple matter of (its) commercial interests", according to its own manager.
Yes, the same EPO that routinely uses "data protection" and "GDPR" as a pretext for hiding or covering up its corruption and white-collar crimes (it even uses that as an excuse for refusing to obey courts' orders)