Meeting Names for Scrumban Team

The term "Scrumban" is not a well-defined term, but it generally refers to some combination of Scrum and Kanban. It could range from using a couple of Kanban practices, like a board to visualize workflow and WIP limits, to something more complete and comprehensive, like Scrum.org's Professional Scrum with Kanban as described in the Kanban Guide for Scrum Teams. However, if you don't have key Scrum elements, such as the Sprint timebox, I wouldn't recommend calling what you are doing "Scrumban" since it doesn't appear to have much related to Scrum.

That said, there are some terms that may help. Terms like "strategy review", "operations review", and "service delivery review" are used by David J. Anderson in his description of the Kanban Method. Other people use terms like "flow review". I'd recommend seeing how people tend to use these terms and if those uses are similar to your use case, using the most appropriate words.

We recently spun up a new Scrumban team that doesn't work within sprints; they work from a Kanban board using the pull system.

That's interesting. Many of the Scrum Teams I have trained work from a Kanban board using the pull system. Doing so is not viewed as a contra-indication to Scrum implementation.

I'm wondering what we should call some of our meetings since I'm unfamiliar with Scrumban specifically. We have a "Sprint Review" coming up to inspect and adapt the work being done. What should this meeting be called since we don't technically have sprints?

Do they actually intend to hold such events at regular iterative cadence, as opposed to whenever a certain trigger or threshold in their workflow is reached? If so, why?

So the Scrumban team does not have sprints - there is no iteration that they work toward. They work on items and pull them through the workflow. We still have the Scrum ceremonies, just not near as often and not on a sprint cadence. We have a Daily Standup, Planning Meetings (once/week), Retrospective (once/month), and Reviews (once per month). I was hesitant to call it a Sprint Review though since there is not a sprint with this team. 

The words we use to describe things are indeed important for transparency. The most important thing to recognize is that there are no ceremonies in Scrum, but there are events. Each is a formal opportunity to inspect and adapt something.

My advice is to first focus on what triggers the events your team intends to observe, and on what is being inspected and adapted. They can then be named appropriately.