A simple traffic warrant is they type of thing that isn't going to result in serious problems 90% of the time . . . the other 10% of the time, it can cause a real headache. It all depends on individual circumstances. The good news is that, unlike other warrants, traffic warrants can frequently be dealt with remotely just by making a payment. That will of course vary depending on individual cricumstances and jurisdiction, but usually money solves it.
This whole thing still sounds strange. Generally speaking, there are two types of traffic camera enforcement schemes. In one scheme, the driver of the vehicle is liable for any violations and the ticket carries the exact same consequences as if a police officer wrote a moving violation. In this scheme, the driver must be positively identified. Frequently this is done by reviewing the drivers license photos of those residing at the vehicle owner's address. Failure to respond to this type of ticket could result in a warrant.
In the other scheme, the vehicle owner is strictly liable for any violations irrespective of driver-- they are essentially like parking tickets. Non-payment of these tickets can have consequences, but they are civil consequences. I am unaware of any jurisdiction operating under the strict liability scheme that issues arrest warrants to vehicle owners.
So it would be surprising that a ticket issued under either scheme would yield an arrest warrant against someone other than the driver unless that person looks a lot like the driver in the photo or the issuing agency is totally careless. (The OP says "husband", so I am assuming a difference in gender though that it is not a forgone conclusion). Is it really an arrest warrant, or scary misleading boilerplate from a private traffic camera company trying to collect on a ticket because they get a cut of it.