I can’t really find a clear-cut answer online.
And so of the oak; it loses its leaves every year, of course, but even then it is not dead. “So,” says God, “you have seen the tree in winter, standing naked and bare, without any sign of life, its roots buried in the hard and frozen soil, and its naked branches exposed to every blast, without a bloom or a bud; yet the substance is in the tree when the leaves are gone. It is still alive, and it shall, by and by, in due season, bud and bloom.
A leafless tree symbolizes hope for a new beginning.
Leafless Tree Meaning