https://ew.com/tv/2018/09/13/modern-family-character-death-season-10/
My guess?
We know it won't be one if he main cast but if she dies it would affect Claire, Mitchell and Jay.
Yes, the grim reaper will visit the show in an episode airing in the first half of this season, co-creator Christopher Lloyd tells EW. "We're handling some bigger life events in this season," he says. "We do deal with a death, which is certainly a topic that families have to deal with, and on television, it's not easy to do because that's a heavy subject. But at the same time, it would seem unusual for a family not to go through it."
Not surprisingly, Lloyd isn't revealing who is headed six feet under — or if it's one of the main family members — but he promises that he/she is a "significant character on the series" and the death "will be a moving event — and an event that has repercussions across several episodes."
My guess?
We know it won't be one if he main cast but if she dies it would affect Claire, Mitchell and Jay.