If you browse a folder containing lots of directories by using the next or previous buttons or keyboard shortcuts etc., it is quite easy to get lost, e.g.:

You have 100 icons, all looking the same because all are folders. You visit one of the folders. You do something with the files in there or not, whatever. You want to go back, so you click on the `back' button or use a keyboard shortcut. You get back to the list of the 100 icons. Now you want to do something with the folder you just visited. While it is convenient that the folder is visible in the view, you have to search for it because it is not selected.

So, if the folder you just visited is a subdir of the folder you currently see, then it would be very convenient to either select it - nothing is selected anyway in the current version -  or at least highlight it: Make it blink, draw a red box around it, let it say `I want your attention', whatever.

Btw: If the content of the previous folder changes and you go back, you should still see the last visited folder in the view (that means thunar should automatically scroll to it). I don't know if this is the current behaviour already, it just came to my mind.