We were looing into building a REST API integration to Export/Import content from a cloud hosted WEM instance. Does the API provide this option?
Depends on version of WEM and you setup and end use case.
There may be more than one solutions if you have right WEM version and setup.
Generally, with WEM 16 onwards there is Mgmt stage REST API which can be used to read/write content items using REST API.
If you just need to access content and not write to WEM then delivery stage REST API solution has been available since WEM 10.5 onwards.