https://softwaredoug.com/blog/2022/12/26/surpries-at-hi-dime... it's both much more likely to be actually orthogonal and almost always very close to orthogonal.
If you're picking a random point on the (idealized) Earth, the probability of it being exactly on the equator is zero, unless you're willing to add some tolerance for "close enough" in order to give the line some width. Whether that tolerance is +/- one degree of arc, or one mile, or one inch, or one angstrom, you're technically including vectors that aren't perfectly orthogonal to the pole as "successes". That idea does generalize into higher dimensions; the only part that doesn't is the shape of the rest of the sphere (the spinning-top image is actually quite handy).