I haven't seen anything indicating that inspire health alliance will be the primary contact on DAS calls, or that they will even be involved directly in every case. The WDW DAS site does not indicate this, and from USA Today's article:
"
Registering for DAS involves meeting with a specially trained cast member, who can determine if DAS is the right fit."
"
Virtual video calls will be similar to what existing and past DAS enrollees are used to having with cast members, but Disney is also partnering with
Inspire Health Alliance, whose experts
may be brought in."
Both of these quotes fit everything I've read - that inspire health alliance will train the CMs for virtual calls, and that inspire health alliance *may* be additionally consulted beyond that.