I don't think he wants to say anything definitive because he knows that if he flat out confirms the Marvel Television shows aren't canon, he'll upset a significant amount of the fanbase. By keeping mum, he let's everyone believe what they want. I for one don't expect him to do anything with what Marvel Television's set up (Jarvis in Endgame being different due to Feige himself actually being involved) but at the same time I don't think he'll ever make some statement that they're not canon.I honestly wish Feige would just come out with a damn list so we know what is canon and what is not. I think he owes it to the fans that are 100% invested in the MCU.
The fact that when he did his Reddit AMA he ignored any question related to Marvel Television shows this.