I fail to understand all the excitement. If this training results in one girl getting out of a forced prostitution situation - I think it was worthwhile.
If staff was trained to spot "forced prostitution", for all I know this might make it easier to be left alone for ladies that have made the personal choice to be in that - trade. Other than assumptions by other people, there is nothing that suggests women can't sit alone at a bar, invite other travels to their room etc.

There are several Marriott properties that have the reputation for actively helping connecting guests with workers in that industry - W South Beach comes to mind - so I don't think there is a generic corporate attempt to fight/regulate anything. Many many years ago I was upgraded to the presidential suite at a property in BKK, and turned out the suite came "fully staffed" - one of the several moments in my life where I regretted civilized upbringing before declining this one aspect of the upgrade.

Regardless - I don't really see the problem - sure, there will be the odd false positive - but if this enabled some women to get out of a duress situation - probably worthwhile.