Even 10 years ago, it was already very common to assume that "open sourced" softwares should necessarily open their development process. I have several first-hand accounts and tried very hard to decouple them to no avail. And this confusion was built into the origin of that term; esr's highly influential The Cathedral and the Bazaar [1] exactly suggested that after all. It is no surprise that the term became even fuzzier by now.

[1] https://www.catb.org/~esr/writings/cathedral-bazaar/cathedra...