Well like when it becomes tree-stuff it is often split up, the tree will retain some water as part of its inventory of healthy-tree biomass but also some of the H and some of the O in the H₂O gets turned into sugar and starch and structural carbohydrates and proteins and stuff.

You can regard those other substances as a reservoir for water, in a sense, because over time as they are metabolized or whatever happens to them they may break back down into water again. As part of the tree's life cycle.

But in terms of where it ultimately goes? Sure absolutely, someday the tree will die, and when it dies the tree will decompose, and some part of the tree's biomass will be eaten by bacteria, fungi, and the other usual suspects. During that process much of the tree will be turned back into water again. And then go be part of the soil, from which new sprouts will sprout again, and so on and so forth.

Some statistically minded biologist might be able to give an estimate of how long your average water molecule remains water continuously over a timeframe like that (let's say several hundred years). It might be that a lot of the water a tree consumes just always remains water. Or it might be that most of it changes form! That is an interesting question.