I just updated to Sublime Merge 2091, by following the standard popup dialog. After updating, there is a hanging Sublime Merge (2083).app file that is left over in my Applications folder (I am on Mac), besides Sublime Merge.app that corresponds to the new 2091 build.
Thus, I have these two files in my Applications folder after updating:
Sublime Merge.app
Sublime Merge (2083).app
...
I presume this is a bug, since the 2083 file should have been automatically deleted.