Some more technical background information:
We will always try and support firmware changes in the existing range(s) of a protocol. This off course depends on the nature of the changes, but supporting multiple firmware versions in the same protocol range is the preferred option. There will, in that case, be no impact when updating to the latest version as it’s similar to any other bug fix or newly implemented feature.
When the changes are too distinct, a new range will be created specifically for that firmware version as long as it's still in line with what was available in the previous firmware version(s). More details in this case can be found in the FAQ mentioned by Sammy.