I think the question is whether you are disagreeing for pedantic reasons or are actually trying to contribute.
If you are trying to contribute, you will use the phrase backward compatible as we always do: my old code will still run after the change.
If you are trying to be pedantic, you will choose a new way of looking at it: My new code will not work if you go backward in time.
I don't care. I will swear to never write a dangling comma for any engine that doesn't support it. Also, I will swear to never use an engine that doesn't support it if once that does exists... Just as I did with Javascript.
If you are trying to contribute, you will use the phrase backward compatible as we always do: my old code will still run after the change.
If you are trying to be pedantic, you will choose a new way of looking at it: My new code will not work if you go backward in time.
I don't care. I will swear to never write a dangling comma for any engine that doesn't support it. Also, I will swear to never use an engine that doesn't support it if once that does exists... Just as I did with Javascript.