K2, The regs should help with your question.
For the initial plan year of employment, eligibility is determined by expected hours of service. For later plan years, eligibility is determined by actual hours in the prior plan year.
For your question in post #5, the person is not a participant for the year ended 6/30/16 because he/she was not expected to work 1,000 hours in his/her first 12 months. When he/she did work 1,000 hours in the plan year ending 6/30/2016, he/she became eligible 7/1/16.
I suspect the article you quote is saying that the person doesn't become eligible mid-year when they reach 1,000 hours during the year. But, rather, they become eligible at the beginning of the following year.