A lot of people get scammed. I have funds at Fidelity and they are great in general. I also like Schwab. My guess is in order of decreasing odds.
1 Conversational.
2 Concerned about a customer being the victim of fraud.
I don't comprehend how pulling money from your own account could amount to money laundering, if laundering was occuring, I would think it would money of suspicious origin going INTO an account.
All taxable transactions from a retirement account are reported.
I am a very chatty person but would never ask why a person was pulling money, but might say "hope it's for something fun" or something like that.
I would not answer the why question posed in the thread, but wouldn't move my money around because of one idiot on the phone unless it was a company policy to ask, and potentially prevent transfers if the right answer was given.