You should check your manual to see if there is a maximum bucket width specified. Some manufacturers do this because a wider bucket will put more stress on loader arms if you "catch" a corner of the bucket on something. If there is a maximum spec, running a wider bucket will typically void your loader warrantee.
That being said, I see no operational issues if you're careful. I'm sure you're aware that a bigger bucket can hold more stuff which means more weight and there may be situations where you can't lift a full bucket of material depending on the materials density.
Why do you want the wider bucket?