Last season, it was discovered that the Tree of Harmony was both alive and sentient. With roots as far as Twilight's School of Friendship in Ponyville (as far as we know), it was self-aware enough to project a psychic manifestation of itself in the form of Twilight in order to help guide the new!Six, regardless of the fact that some of them died from it.
Pointing that out because Sombra blew that tree up. Not only that, he shattered the Elements of Harmony that were supposed to sustain it. I'm not barring any magical Mcguffins in order to bring it back, but until then as far as we know Sombr