One potentially alarming sentence in this article is "Wix will open up DeviantArt’s repository of art and creative community to the Wix platform, giving Wix’s users access to that work to use in their own site building." Exactly what do they mean by that? Will it be opt-in? Will it only cover art that's already under Creative Commons? Will be it all Creative Commons? Does a Wix site count as commercial use? I can't i…
Based on the Submission Policy on DeviantArt's site, the essence of the agreement seems to be that as long as the work continues to be on DeviantArt, any DeviantArt site can use it royalty-free under a non-exclusive licence. The artist (or other submitter) is free to remove the work from DeviantArt at any time, and with some provisions about orderly handling the work is then no longer available for use on DeviantArt sites under those terms. The copyright and related legal rights in each work remain with the artist throughout (or with whoever else had them before, but they're not automatically transferred to DeviantArt).
Whether the acquisition means sites run by Wix now count as successors and therefore enjoy the royalty-free rights regarding uploaded works is one for the lawyers, but even if it that is the case, it seems that anyone who objects can simply delete their work from DeviantArt and in doing so withdraw the consent required to use the work on any other sites as well. That being the case, it would seem unwise for Wix to try to pull a fast one here, and a more collaborative approach would seem to be in everyone's interests including Wix's.