As someone who still go's to meeting regularly and talks and associates with the other JW”s, I think the reason for the removal of the book study is that the WTS has realized that the R&F have had enough and can’t keep going to all these meetings, the Book Study is the least attended of all the meetings.
The 5 meetings arrangement was thought of about 50 years ago a time when just the man of the house would work, and the children needed only basic school, so there was lots of spare time to go to these 5 meetings, but today both Man and Woman need to work just to make ends meet and what was considered to be basic school isn’t basic enough anymore, children need more education just to get the same job. Something’s got to give and it was the book study that gave in.