I concur. My bath reno of decades ago only has one seam and the tiles cracked on it. I strongly recommend doing something preventative like anti fracture membrane.Next time try to offset seams more and use fewer pieces. You'll have a little more waste but less likely for cracks to come through tile.
In my case I'm not sure if the problem is due to the seam in the board or the fact that half of my wall is exterior solid masonry and half wood frame.
If you gamble and the wall cracks someone's not going to be happy. Doing it over will be unpleasant. That or a tub surround.