That's my understanding too TheEndless. The protocol includes power for the stick via the MHL and also control protocols. So it is the TV that's getting info from it's own remote, then sending the info to the stick.
True that only the newest of TVs will have it. But.... without it, if you needed a separate power supply and separate remote... you'd have a roku2.
I've often wondered over the years about why the new "smart TV" standards were so dumb....building the computer into the TV
with no way to upgrade hardware. I realized, of course, that a hardware manufacturer wasn't very motivated to make, for example, a PCIe slotted TV with a plug-n-upgrade option. You know, unplug the 3 or 4 year old hardware, plug in the new. Of course, that would add a few bucks to the manufacturing costs and complicate the interface. They want you to give the TV to the grandkids and buy a new one. I'm surprised that this MHL standard even made it. lol.
I've always thought the computer and TV would merge. Didn't realize they would build it all into the screen. The screen is one "generic piece" that should be swappable. Like computer monitors used to be...just monitors. Now everyone uses TVs
This standard was meant for smart phones and such, I believe. Hey... Roku Phone...
The other way to look at it is... why does a TV manufacturer want to be in the software/computer business? Why not just produce a MHL based TV and let "the other guys [like Roku]" produce the software/box for "smarts". Then the only thing the TV has to have is a small processor for dealing with the remote and protocol. The EXTERNAL device would do the rest and be upgradable. That's the future market they're trying to get in on, I'll bet.
EDIT: HDMI->MHL