I didn't want to open updating the games during voting, because people could continue working on their entries, and Itch don't offer "fixing bugs" option - it's either allowed to do whatever you want, or nothing at all.
I could remove an entry (which could be then updated) and then allow it to be submitted again, but you'd lost any votes you had so far, so I'd say it's for critical game-breaking bugs only. You will be able to fix your entry right after voting will end though.