If it's disabled to be permanently open, I'd leave it. The only time you'll need shutters is when it's near 0 out and the engine can't build enough heat.
And when that happens, It's easy enough to just put cardboard on the front and run it like that until it's no longer needed to do so.
Most of the time, those shutters are disabled because they didn't open once and caused an engine overheat.
After a lifetime in school bus service, they can be worn out and hard to get operating correctly again. Mine, for instance, are disabled.
Don't feed the trolls.