I think it's matching this:

Comment=Edit text files

This does not happen in run mode (Not in my testing atleast)

It's specifically in drun mode that it happens, It might be because the fuzzy match is picking something up in the meta data in the .desktop file for vim

Would it make sense to have the name give more weight in the matching compared to the other meta data?

Not sure if this is already supported or not, but is it possible to order the results for fuzzy search based on how much it matches the results?

For example when I search for files in drun mode, I get Vim at the top of results and Files aka natilus below that, when I think Files is a better match and should be at the top

I found a stackoverflow question/thread that mentioned something about GIO being deprecated?

I want to use terminator instead of default terminal in Ubuntu mate. I changed it in dconf Editor but the entry is DEPRECATED because managed by GIO.

https://askubuntu.com/questions/724810/how-change-default-terminal-in-open-in-terminal-in-gio

Does this mean that we should be using something else?

What do you mean when you refer to GIO in the context of this thread, as I'm currently also trying to get drun mode to launch with kitty and having a bit of trouble as you have mentioned that gsettings org.gnome.desktop.default-applications.terminal exec seems to be ignored.