Not everyone agrees with this definition. If the source is open to read, for me it's open source. The website you linked is an opinionated view on what open source is.
Not everyone agrees with the OSI definition but I'd say almost noone agrees with that definition there.
I think most people understand what you are describing as "Source Available". Could even be a commercial project.
That’s called “source available”. Open source colloquially implies open license.
You can define however you want, but it's not Open Source. What you mean is "source available".