Dispatcher reported receiving a message from a flight crew who reported the ENG 2 A/I VALVE failed in closed position.

Narrative

I got a message from the flight during their descent around FL240. I responded that same minute for them to contact me on 1XX.X A few minutes later they sent another message they wanted phone patch with MX. I told them again I was on 1XX.X but that they would be descending below usable coverage. I never got a response via ACARS or ARINC so I contacted ARINC to do a phone patch. I was still unaware of what the MX issue was; so I messaged them that ARINC was going to attempt to contact and asked them what the MX issue was. I finally got a response 10 minutes after my question via ACARS from the crew indicating ENG 2 A/I VALVE FAILED IN CLOSED POSITION. By this time they were at approx 7;000 and already in icing conditions per the charts that I referenced. The safest course of action was to continue to ZZZ as they would descend below the forecast icing.The Captain called me after landing and debriefed me on what happened. The ENG AI V/V was failing intermittently. When the valve failed they were already icing conditions. He said they did not get my messages for a while and later got them all at once. So they talked over a plan themselves to descend below the icing and increase speed to increase the TAT.