Sorry, that cnet article is 2 years old..which is an eternity for Win10...the option isn't even in the 'System' section anymore. A more up-to-date description I found at https://www.lifewire.com/how-to-change-file-associations-in-windows-2624477. But there isn't an easy method to de-associate a filetype from every standard app provided by that 'user-friendly' (or should I say user-infantilizing) OS.
However, it's only a matter of taste. If Acrobat is associated with .dbf, no harm is done. Nothing happens, as long as you don't double click a .dbf. Then, if you do that, Acrobat tries to open that file, and fails. Again, no harm done.
Of course, nobody should edit or manipulate a .dbf, although it is possible, if done very carefully.