China doesn’t broadly want a weaker dollar, at least not against the yuan. Until very recently they actively worked to strengthen the dollar in the pair.

Chinese currency policy is broadly about controlling their domestic population not about foreign policy. Between keeping their domestic manufacturing industry going and keeping their more affluent populations power in check you’ll find most of the motivation for what they do on currency policy.

This move gives one less reason to allow a currency transaction and thus one less way for domestic manufacturers (and importantly their management) to get around those capital controls.

As European Chinese business increased that became more important and Duetche is dominant in fx, being able to handle effectively everything now means European businesses won’t complain either.