wpgraft never reads Oxygen’s data. There is no exporter, no importer and no shortcode translator anywhere in this, by design, because those are the parts that break. wpgraft reads the page as your browser rendered it: the real elements and the real computed styles on each one, at every breakpoint you ask for. It then rebuilds that as Webflow’s own native elements, with the styles written into Webflow’s own fields. Nothing that arrives depends on Oxygen still existing.
This move crosses platforms: Oxygen is WordPress, Webflow is not. There is no plugin and no server involved on the Webflow side, because the copy reaches the Designer through Webflow’s own clipboard format, the same mechanism that moves elements between two Webflow projects. Your Oxygen page stays where it is; nothing is migrated away from it.