Yeah, disclaimer is there.
You did very well.
The FP said, don't know if 6 digits are required (most definitely is), keep a record of your original (we're human, mistakes happen), and the question about carrier support came up - take your phone in for help, and if they're doing their job and notice the discrepancy, they won't think you changed your MSL. They're more likely going to think that you have a stolen phone with someone else's ESN.
None of which is an issue for the extremely conscientious who won't take their phone in.
For those of us known to make mistakes or misplace things, I think that the disclaimer makes sense.