NOT WITHOUT AN INDEPENDENT WIFI connection. Chromecast has to be using wifi, you cannot hotspot from your phone to chromecast AND use chromecast. Your phone and Chromecast have to be connected to a different wifi network, not the hotspot. So no, you are incorrect.
Hi, I'm also very interested in this topic and still looking for a solution. At first I smiled at my boss and his iPhone, because Apple TV is needed for a direct wireless transmission. Now I can hardly believe that Google deliberately omits this standard feature. I am very disappointed.
Are there any news?
I know this an old thread, but I want to make sure that the solution to your problem is known: Connect your Smartphone (Unlimited Data Plan) via USB cable with a WLAN router that supports 'USB Tethering'. I use a AVM Fritzbox 4020.
This question has been asked a couple of times... I think I've posed the question to a couple of peeps. Originally I thought this was a hardware restriction, but seen that one individual stated that it was working on a Pixel ROM https://forum.xda-developers.com/showpost.php?p=74365223&postcount=4 It's possible that when the ROM was ported over, the settings necessary came over with it. I haven't gotten too much deeper than this, but certainly would like this feature as well.