Change Happens.

You get a letter from your health club announcing they've changed their membership rules and enclosing a new multi-paged rule booklet. You immediately wonder what that means, but you'd have to investigate to find out. You probably don't bother, but a residual doubt remains.

If they had simply sent a list of the changes they had made (in the form of the relevant before and after paragraphs), there would be no suspicion that they were trying to sneak something past you.

Change happens. Change is unnerving. It's also a great opportunity to build trust.