There were 230 last year, which is a very small number IMO, and there were only about 140 the previous year. This is a sudden trend that they're trying to nip out early.
I can't speak to the officiating part of it...my only issue is that I just don't see the actual games being impacted as much as people say. People here and elsewhere are talking about how impossible it is going to be to play defense, how suddenly it will not be possible to tackle Derrick Henry from behind, etc., and that just isn't the case when 99% of the time, players are just fine using other tackling techniques.