[sszz]

That there is any significant confusion at all means it is not de facto (and if something is right and true based on a definition I don’t think you can call it de facto either...).

The distinction really doesn’t seem that important for most use cases so it’s not that surprising a weaker, possibly more useful interpretation has become common...

[mindcrime]

That there is any significant confusion at all means it is not de facto

There isn't any significant confusion. There is a token amount of confusion, which is pretty much always clarified every time one of these threads comes up.

(and if something is right and true based on a definition I don’t think you can call it de facto either...).

It's de facto, not de jure, because OSI has no authority to enforce their definition, since they don't have a trademark (at least not a registered trademark) on the term "Open Source". What makes it the de facto definition is just usage. By and large, among the people who care about the legal details of Open Source licensing, the OSD is accepted. Yes, there are a handful of exceptions, but that's OK. It doesn't change the basic point.

[sszz]

I guess in my experience, the phrase is routinely used to refer to code availability and often the fact that a licensing fee doesn’t need to be negotiated or paid in order to run the code on our servers (either in an academic or corporate setting), which is a weaker requirement than the OSI definition.

Real usage by real people not particularly passionate about adherence to the OSI definition—to me this is its de facto meaning. I’m not saying it’s correct usage, but it’s definitely real and frequent.

It’s my impression a non-negligible number of people share the same understanding, evidence by the fact that this discussion apparently is recurring? Even those who corrected the Defold release language knew what was intended, even if they said it was incorrect usage of the phrase.

Your response assumed the number of people who use the phrase with a looser meaning is small; I just don’t think that is true based on my day to day experiences.