Pseu, the term oral tradition isn't exclusive to any culture or even humans. Blackbirds and parrots actually do it and I'm sure many other creatures. It is just a very simple process of passing from one being to another voice to ear and then reproduction in a slightly or greatly altered form.

I understand you are talking about how we use the term in folk music. fair enough. The example I gave was at the very basic simple end. Yes, others will qualify this and talk about passing material from generation to generation, or within a particular culture or generation, but that's just one way of looking at the term. When we discuss it in terms of folk song the vast majority of times we are talking about how the songs become altered over longer periods, but where are the limits of this 'longer period'? In my book the lower limit is as I described. Steve Roud gives it a little longer. Who's right? Perhaps we both are. Again, like much of our terminology it is not precise with rock-solid boundaries.

Cultural appropriation and language boundaries are irrelevances when looking at the meaning/usage of the term.

Saying that pop songs can't be part of oral tradition is ludicrous in the extreme. As soon as little Jimmy hears the latest piece on his hifi and starts singing or whistling bits in the bathroom that is the oral tradition in process.

The alterations that come about due to oral tradition are something else entirely. That's what we call the 'folk process' for want of better terminology. We can discuss the process in more detail if it helps.