Sometimes the humorous term "nine fives" (55.5555555%) is used to contrast with "five nines" (99.999%),[18][19][20] though this is not an actual goal….

Maybe Microsoft misunderstood the assignment, and thought this was a goal. At their current rate, it’s certainly more achievable than the more traditional “five nines”.

As an aside, I love how the following is preferences as “casual”, and then the author starts arguing semantics:

Similarly, percentages ending in a 5 have conventional names, traditionally the number of nines, then "five", so 99.95% is "three nines five", abbreviated 3N5.[13][14] This is casually referred to as "three and a half nines",[15] but this is incorrect….

Ah makes sense. Thanks