There are some examples of sentence 了 that indicate future action which (seems to) have a 要 omitted:
我（要）走了，拜！ - I am going to leave, bye!
I know context usually helps with the issue of time and, apart from that, 我走了 is a pretty common sentence that everyone knows it's an about-to-happen action.
My question is:
If I have any other sentence 了 without any context, for example, "我去中国了", is there a chance that a native listener can think it's a future action with an omitted 要 as in "我(要)去中国了" or does the listener definitely knows it's always a past action?
Thanks in advance!