There are two main types of curing compounds
Oxidising curing compounds are designed to break down over time in the sunlight, generally within 60 days. This should make them easy to sweep off when you start preparing the surface for the underlayment.
But you can never guarantee that they will have fully broken down, especially if the slab hasn't been in the open weather for this whole period of time.
Permanent curing compounds are designed to seal the concrete surface until they're removed mechanically.