Yes, it helps, because it closes off one of the ways they can try to get into an empty home. With a reinforced shutter, they cannot lift it or bend it.
But the shutter is only one part. The other is the door: a basic cylinder, a latch with the key not turned or weak hinges are also a way in. To protect a home from squatters you have to look at both.
What we usually recommend in homes that stay shut for a while:
- Reinforce the shutters that can be reached from the ground.
- Fit a security cylinder with an escutcheon on the front door.
- Check the terrace and patio doors.
It is explained in squatter protection and in shutter security.