I have stayed exclusively at Marriott/SPG properties for 2 years now. All I can report is a fairly regular question asking purpose of my visit. If you answer that question while visibility paranoid, maybe that’d draw suspicion. More than likely, the Q is for their notations and metrics to determine what type of travelers the location is receiving and nothing more.
I meet the majority of my clients in the lobby, and have zero issues. Confidence can make you blend right in with a busy hotel lobby with many coming/going.
I feel you may be overthinking the whole thing. I’d bet any (alleged) policy changes would be surrounding very obvious, reckless, and problem guests that are ruining the stays for others.