In theory device trees are supposed to be a OS-neutral stable ABI. Being able to put a device tree into unchangeable mask ROM is an often mentioned design goal.
However, there is a fatal flaw in the process that makes this a pipe dream in reality. In Linux, these rules only apply to reviewed and merged drivers. And during review any new DT interface will almost certainly be bikeshedded in some way.
So unless your chip vendor has upstreamed ALL their drivers before a device is manufactured, the device's firmware-provided DT will very likely work only against a vendor kernel and requires updating.