Yes in 15.8.1 we released the enhancement to support 2085 characters, however, soon after customers complaint as it was not working correctly. Essentially Excel has a limitation that it will only support 255 characters for hyperlink. So when we were sending the 2085 characters, Excel would trim it down to 255 characters and customers would see broken link. This caused more frustration and customers said it is better to not show the link than to give a broken link. Hence in patch 1 we reverted the changes back to how it was prior to 15.8.1.
Thus what you are seeing is correct that any link longer than 255 will not see the hyperlink.