I'm from BC and there has always been one Saturday morning bookstudy in every congregation I've attended since the 1980's. My father is still a PO and conducts the Saturday morning bookstudy in his house before service for years. When I visited a friend in Seatlle, they had Saturday morning bookstudy, coffee as a group and then service. I wonder if there are still Saturday groups now that the bookstudy for everyone is supposed to be at the Kingdom Hall?
As for the yoga, I used to do yoga myself in my home when I was pioneering, also in the 80's. No one ever said anything to me about it although I didn't advertise it heavily, my pioneer partner and a few of my friends saw my yoga book on coffee table. Wasn't a big deal. My sister, who is a JW goes to yoga class. Some don't approve, but it is not a big major deal here. The west coast of North America is much loser in what is acceptable, especially in California. The congregations tend to reflect the more casual attitudes to traditional morals and activities that is present on the west coast. The same is true in Canada. Many on the coast of BC are seen as "slackers" compared to the super dubs that pioneer back east and go to bethel.