At the moment, the only way to sell Wavelab is on a USB eLicenser, as is mentioned in the Resale Wizard. You cannot return a licence to the eLicenser server and turn it back into an Activation Code.
The tl;dr of what follows is that Steinberg’s announcements to date do not reveal whether Wavelab will not move to Steinberg Licensing until a future paid update or whether Wavelab 11 will transition in a future minor update. At this point, Steinberg might not have decided on their preferred transition strategy for Wavelab.
Wavelab will move onto the new Steinberg Licensing at some point, but this might not be until a new paid update comes along (the initial plan is to move products over at a paid update). The long period between paid Wavelab updates, plus the likely desire of customers to move entirely to the new licensing system once most of their products have moved over, might mean Wavelab 11 will move to the new system at a future minor update.
At the moment, Steinberg has not revealed any plans beyond Dorico 4 being the first product to switch to the new licensing system, followed by Cubase 12 and presumably then Nuendo 12 (as Nuendo releases happen shortly after the corresponding Cubase release). A paid update to HALion next year has also been mentioned, which might trigger a broader transition to the new system. Customers with HALion on Steinberg Licensing will likely want to buy new content packs on Steinberg Licensing, as well as transition existing content packs from eLicenser.
Steinberg presumably will monitor feedback as the first products roll out on Steinberg Licensing, then refine their plans to move over their entire product line.