I don’t know but are you really sure users like it? Not everyone, quite few I would guess, uses forum sidebar wide open and if you remove the icon you make using chat more ackward. And with mobiles it will happend for sure because with smaller screens using sidebar all the time is no option at all.
Sure, chat icon is a bit problematic because it opens the very first channel and the sidebar gives more versatile tools jump around. But it is not that stranger behaviour than what like latest gives.