The syntax is still that of a regular Org link: either a plain link cite:link or a bracketed link [[cite:link][description]]. The semantics of different parts does’t matter in this case. Org-roam is not going to process any links. It just figures it’s a cite link an updates the database table with ref backlinks accordingly.
I just checked Org-roam for stuff related to Org-ref. It looks like Org-roam now uses a more general approach of matching against org-plain-link-re to determine whether a ref is a link. So as soon as Org-cite registers its links with Org parser, e.g. updates the regexps such as org-link-plain-re, there will be no difference. And it’s definitely going to do that. Previously, Org-roam was using org-ref-cite-types to match the cite:links. Now, it does not seem to use this variable anywhere anymore, so actually it looks like Org-roam has already made a seamless transition to Org-cite that also works with Org-ref, @jethro? There is also an Org-ref-specific workaround, which deals with a bug in Org-ref, but it’s not related to parsing cite:links.