All they agreed to was that the DRIVER could not enforce seating…..but it isn’t even clear in the case of this moiseres that the driver did that (we don’t take her word for much). I have been on many non-frum sherut taxis in EY where most riders were frum and we ourselves arranged our seating. The driver is not going to enforce mixed seating either.
And you don’t know what the company’s next move is. My guess is that if rabbonim ossur the bus because it becomes mixed seating, or if the clientele becomes uncomfortable, something will happen.