It could be yep. One of the things that makes it a good fit for this use case is that Flecs has a query language that supports things like graph traversal and joins. Combined with either the builtin REST API or some custom protocol you could use it as a realtime in-memory database (which is what I use it for).
Unless I'm mistaken, Unreal hasn't had an official blessed ECS system relying on other things: from just having regular objects to reading data from data tables.
