I have always heard even what you eat the day before can affect your cholesterol levels. However here in the US some doctors are telling their patients not to fast for the test anymore. The theory is to get a more accurate rate of what daily is going through your veins and that is more accurate. ( I have a bias thinking they just want more people on statin drugs, but that's me) I have not ever had to care as I'm a vegan and don't ever have any cholesterol issues.
But here is an article on it that explains the new trend.
https://www.statnews.com/2016/04/29/fasting-cholesterol-testing/
The NHS guidelines in the UK also say it is not necessary to fast. However, the reason given is because fasting tests have to be done early mornings to avoid too much stress on the patients. This means in GP surgeries there are waiting lists for these tests, whereas non-fasting they can be done at any time of the day, so more tests can be done in one day. It is for logistical and practical purposes, nothing to do with accuracy. However, should the triglycerides be high, then a second test is ordered and that has to be fasting.
That article you linked to says non-fasting gives a more accurate result of what our triglycerides are during normal times for most of the day, and produce a "normal" result. That is codswallop in my opinion. Our cholesterol changes like the wind from minute to minute, just like our blood glucose and blood pressure do. There is no "normal". In order to have a consistent result, fasting is the only way. In the UK we are told fasting is not necessary, but I always fast for mine and can therefore compare each test and look for realistic trends.