I have also seen the way my slave cylinder bracket deflects. But I doubt that this will lead to failure, but it certainly effects the amount of travel available in the clutch pedal and the clutch reconnects with only a small amount of foot movement. I don't recall this being an issue before I changed the clutch last year, so it occurs to me that the new assembly has a heavier spring rate than the original one, so the bracket deflects more.
A reinforcement mod is on my to-do list (before the summer I hope).