I 100% believe they mean you can put your 1-2-3 onto one button. They were talking about REDUCING button bloat. The way that twitter user explains it would only give the option to EXPAND button bloat, or keep it the same. Which based on what we saw with Viper and Pictomancer, is not the case. They also stressed that Viper and Pictomancer have the same number of skills as other classes, but the buttons are reduced because of the new system.
I do not believe for a second that they are giving us the option to UNLINK actions that ALREADY share a button, over COMBINING buttons to reduce them when the POINT is controlling button bloat, especially for controller players.