As far as I know, the top most dopesheet items are always the bones that you selected last. It's kinda helpful in that way. If you (accidentally) deselect your selection, the bones stay where they are in the dopesheet list.
Some sorting might actually help, but I think, sorted list or not, scrolling up and down to look for a dopesheet item is just as bad as scrolling up and down to look for a tree item
that is to say, a big headache.
I'm handling skeletons with easily 30+ bones. The tree's alphabetic ordering doesn't help at all. In my case at least, I'm pretty sure it won't help in the dopesheet. Most selection operations are best done in the viewport where you can see what you're selecting, instead of selecting them by name in a list of names.
What's your particular use case for sorted items in the dopesheet though? Might be handy.
