IPL is a light treatment that comes up often when people ask about melasma. Here is what the sources say about the risk.
What DermNet says about IPL and melasma
DermNet says microneedling, intense pulsed light (IPL), and lasers carry a high risk for relapse and the disease becoming more resistant to treatment, so they require expert use.
The same page says chemical peels and lasers can be used with caution, but carry a risk of worsening melasma or causing post-inflammatory hyperpigmentation.
What that means for your decision
IPL is named among the options with a high relapse risk, so it deserves a slow decision. Ask any provider you are considering how much melasma experience they have.
Further reading on melasma and IPL
The MedlinePlus entry on melasma is a plain overview of the condition. A paper titled Intense Pulsed Light Attenuates UV-Induced Hyperimmune Response and Pigmentation in Human Skin Cells looks at IPL and pigmentation in human skin cells.
Where IPL risk shifts during a course
The answer shifts with where you are in treatment. Before a first IPL session, and again if the patches return, ask your provider to walk through the risks above.