The truth is that if you apply for credit while an acct is being investigated (good or bad acct) it is not considered in the FICO evaluation. This is a "loop-hole" in the system that they do not what you to be aware of so they encourage you not to apply.
It is a good chance that you can get approved for "instant-credit" opportunities while negative accounts are being disputed. I have put it to practice and it works.. You can use simulators to determined what your FICO would be if you paid off your negative debt. In fact, when you dispute the items that is used in the simulator to increase your score "if brought to zero" your FICO will reflect that score and much more becuse the system trats the accounts as if they were not there when applying for new credit.. Try it!!
I can only assume that this must cost a pretty penny to correct in the program with the CRA and it is much more cost-effective and clever to send out the blurb you received. I like your curiosity!!
The blurb is a cover up for RISK MGMT!!