Not exactly. The point of backwards compatibility as we have had in all previous generations is that since this is a mesh network, as long as the older device is in range of a repeater, all the devices can coexist on the same network. If a particular hop is long range to long range, we can take advantage of that. But you could have a long range device within the shorter distance communicate successfully with a short range device. that still counts as “backwards compatible.“
That’s how it works now for the fifth generation (zwave plus) and the older third and fourth generations (zwave classic). You can mix and match these on the same network. But you obviously only get the longer range for a hop if the device at each end is capable of that distance.
Z wave from the beginning specifically has not wanted people to have to buy new light switches in order take advantage of a newer generation hub.
My guess is the firmware will be updated on the older devices to allow for networks with more than 232 IDs, but the difference in transmission strength won’t matter, again as long as there is some device within single hop range of the older devices. 