That’s not how it has been working ITG.
A legacy unit is just one that we no longer are in production of.
We have supported software updates for many unit models for years after stopping production of them.
Whether we will still come out with software updates for a particular model is dependent on many factors, most of which I do not know about. I do know that if the unit does not have the capability (Ex: Ethernet connection) or memory space, it will not get the new update.
Don’t ask me if XX model will get a software update or not as I usually don’t know about them until they get posted to the My Humminbird accounts.