Another thing not mentioned in the article is for delays >10s, a loading bar that fills slower at the beginning and faster towards the end feels faster than one filling linearly or accurately reflecting progression.
Using load times to convey something while users wait is fair however I would bet shorter loads times always beats however good a filler, unless your business is to trap users in load times to feed them more ads of course, in which case that's a whole other problem.
That actually makes a lot of sense, because "filling slower at the beginning" provides a worst-case estimation of total completion time. So users are a lot less likely to be negatively surprised by a random, unexpected delay.
Using load times to convey something while users wait is fair however I would bet shorter loads times always beats however good a filler, unless your business is to trap users in load times to feed them more ads of course, in which case that's a whole other problem.