Witnesses have been trained to adjust their presentation to fit the audience. When they're around "proper dubs", they talk about the proper things, you know, the meetings, service, and such theocraptic crap. When they're around "worldlings" they have their choice of being good dubs, ordinary folk, or somewhere in between. But when they're around like-minded less spiritual dubs, they can be incredibly honest.
You ask if there's been an increase... I ain't the all-knowing Hojovah, but I'd say probably yes.
ITA- I was always a double lifer and I could usually pick out the others who were as well. Many that were there with me (and are still in) are still living the double life al these years later. We all look pretty straight and narrow at the hall.
I do think the number of those people are increasing, but there has always been pockets of them in every hall. They just couldn't reveal themselves to everyone. Once you're out or borderline they will feel much safer being themselves around you.