Yup, they were always available at the maximum size of the file.
However, I believe you can still opt out of offering them, or maybe you even have to opt into the scheme.
I remember a couple of people a few years back saying that giving a free image did have a boost to their sales for about four weeks; but now even having the Image of the Week (not free) doesn't guarantee a lot of downloads - gone are the days that an IotW would usually get hundreds of sales (indeed they once expedited a new contributor to exclusive by that means).