Hi! I know the forum from last year is gone, but I know people were reached out to around early March (March 2nd) for the UMass CHE program. I remember people saying to make sure you also completed their SPIRE supplementary application as that can delay the process a little bit if you do not I am not sure if interviews are required, but I do remember they reached out to some to get a better idea of faculty matches/more information.
I hope this helps, wishing you the absolute best!