I always thought that too.
Could it be that since the move to a symmetric 4-arm spider, it's possible to orientate the chainring bolt holes so they sit under the teeth rather than the grooves, so don't foul the chain rollers (which are usually wider than the plates)?
The bit about "optimises your pedalling effort" is bullshit because they're still round rings, they've just put the bolts under the teeth to get smaller rings onto 110 bcd.
I always thought that too.
Could it be that since the move to a symmetric 4-arm spider, it's possible to orientate the chainring bolt holes so they sit under the teeth rather than the grooves, so don't foul the chain rollers (which are usually wider than the plates)?