I'm in two minds about this.
Yes, I think it's absolutely essential that an ISP should disclose that they are performing traffic shaping, to let customers know what types of traffic will be restricted.
However, the EXACT nature of how shaping is applied, in particular which protocols are prioritised on the network, will inevitably be used by people to work around it - often in order to download obscene amounts of data - making the shaping work against the ISP, therefore it becomes a cat and mouse game.