Starting in MATLAB R2023a when you change the Rotation property of an axis label in a 2-D plot, the HorizontalAlignment and the VerticalAlignment properties of the label automatically update to prevent overlap between the label and the axes.
Prior to R2023a, you can set the alignment properties as demonstrated below.
ylh = ylabel(. . .);
set(ylh,'rotation',-90,'VerticalAlignment','bottom')
The alignment properties can also be set directly in ylabel(), too.
