I agree that I would love to see both of those things. They are planning a 100W rated cable to go with their higher rated chargers, see here:
Thunderbolt cables good for 100W and 40Gbps sound cool, but those are fairly specialized devices - I don’t know of any that are trying to take advantage of the FULL Thunderbolt 3 bandwidth that don’t include an integrated cable. So while it would be nice to have the option, the market is probably tiny at the moment. I’m sure they will get there as it grows.