I wouldn't worry about the seam coming apart in a finished wheel, spoke tension pulls it together. Can't see any particular grooves apart from the wear indicator. But it does look like one side of the seam has been shifted quite a bit inwards, which makes me wonder how round the rim is. Deformities close to the seam - particularly what looks like a pinned seam - are difficult to correct, as the seam tends to gape when you try to apply the straightening force.