I would have liked to see it as an option field for fully intact Majors teams. That would make it in availible in our area, where our fence limits are at 200 feet. We'd just impose that 2 1/4" bats be used.
Around here it will be most likely be limited to 11s & 12s.
Not all of the 11 and 12 year old major players wanted to play l50/70 last year taking the ones that wanted to play we formed a few of teams and played In-House and also played Inter-League around the District (weekends mostly).
I imagine it will be the similar this season.
Last year no one wanted the 13s, mostly for safety, especially when you realize that later in the season many "league age 13" kids will be 14.
14s year olds playin 50/70 ??? Not a good idea in MY opinion.