With Wix and OVH it is like it is with any Web or DNS provider in terms of your question.
Taking a look at https://support.wix.com/en/article/connecting-a-domain-to-the-wix-name-servers (which was as easy to find as it is probably to launch some generic website there) I say you have all possibilities at hand. That said: a web hosting is not the same service as DNS. They often come in pairs but can be done independently. So, you have two choices:
- Transferring your domain to Wix and go through all the effort
- Keeping everything as it is - OVH for the domain name and Wix for hosting your web site
With those two options at hand I’d recommend you to check whether Wix offers all technical opportunities that OVH do. I myself migrated to OVH recently because a major German DNS provider I was in contract with before frankly did not achieve proper safe mail server DNS possibilities even back in late 2017. And I am using OVH only for DNS, I am hosting things elsewehere. And that works brilliant. If Wix offers you all the technical stuff OVH does, go ahead if it is more convenient to have everything in one back-end.
At any point in time any domain can be transferred from any way, so you really have the liberty to choose. That should not be the issue.