Yes TEam Flash did call ZOOM's world Earth 2, Wells however did point out that from his own viewpoint that Team Flash' Earth was Earth 2.
However none of them knew that Team Flash' Earth was the Earth from which all others have sprung. ZOOM informed them of that so that can change the numbering system if they wanted to.
Team Flash Earth could be Earth 1, Earth Zero, or Earth Prime. If they use Zero or Prime, then Well's Earth becomes Earth 1 and that puts Jay on Earth 2.
If they wanted to do that.