I brought this up in one of the hype threads - and there was a little discussion. The feature matrix only refers to the Premium building as being a "bash toy", prior to the stream I assumed one of the levels of the building with no lane/passthrough would be used to bash the building, but so far in the stream at least, there was no bash mechanism shown. The building never lowered to the level with a flat surface/no passthrough to bash. I do see the wording from the video implying the Pro building is bashed as well though.

There were a few shots that just seem to be rejects in the stream when the building was at the first level, consensus being that they hit the thin blue rubbers on the sides of the first floor opening (the second floor opening is wider/doesn't have those rubbers). Those rejects still seemed to count as hits/damage to the building though, due to the fact I believe close-up images show opto sensors just behind the stand-up targets to detect such shots that don't go through the building but break the opto beam. Edit : the Pro video shows such a reject at the 53-54 second mark - definitely seems to hit the blue rubbers and still counts.

Could be they add something in code we didn't see yet, but another poster also pointed out that when the building is lowered to that third level with no opening/passthrough, the ramp returns would no longer route through the building - and would crash into the building or maybe end up falling off the roof - so presumably that will never be used...

I guess it seems the "bash toy" label was a misnomer, unless something changes, or you count those rejects as bashes...