If you don't cure a ham and just brine it, is it just considered a pork roast?
Techincally, ham is the cut of meat (the rear leg of the pig)--so what you prepared was a fresh ham roast, or just a pork roast.  You happened to brine it preparation.

The term ham has also come to mean the cured pork product--or now, with so-calle turkey ham and whatnot on the market, similar cured meat products.  "Fresh ham" emphasizes that you have the non-cured cut.

The thing is:  as long as it was delicious and you enjoyed it, why worry? :-)