If they are violets, there is a very good chance they will reappear from last year's root-stock. The label 'viola' does not clarify the situation - it could relate to violets or pansies or bedding violas or violettas. Reseeding is, in general, an additional possibility.
If in doubt, don't hoe or weed, at least not for a good while yet.

I know they weren't pansies, but past that I really don't know what I bought, I believe the label by the plants just said violets.

I bought them because violets are supposed to be a host plant for some types of fritillary butterflies. Those may not have been the right type anyway though.

It seems alot of nurseries sell Viola tricolor as generically labeled "violas". When you bought it last year, was it in bloom?

yes, they were blooming. They were dark purple but could have had a little more color but I don't remember now. They also sold some yellow ones and I bought a couple of those too.