If I have to widen the seam and am planning to iron the seam to one side, I never rip. I consider it as an extra guarantee that the seam won't ever rip out. My thread is 50 weight so it doesn't add hardly anything to the seam. Now I might would have to rethink the ripping if I was using 40 weight thread.
If I have fabric that is really bad about raveling, I have been know to sew a wavy extra seam within each seam allowance to stabilize the bad material. After one quilt like that, if I see the material raveling, I discontinue the use of it in a quilt unless I am going to sew 1/2" seams. And, I do that when piecing the back, then iron them open.