I wash all of my batiks in HOT water. I would agree that the "better" ones may not run, but after I saw a
Needle turn applique that a friend had done and saw the purpleish running into her white, (she washed it 3 times with pre-treatment and color catchers & you have to look, but MOST of the color came out) and wondered about a batik I bought & washed it with the water turning blue, I made the decision that I would wash & re-iron all of them before they ruined one of my quilts.
It is a personal preference, but when you put so much work intot something to have it "ruined" by running, it is better to be safe than sorry.
Good Luck
Susan