I cannot say I've ever needed to know the charge-rate mode from across the room.
I can say though that I've wanted to be able to plug a device in on both the left and right depending on location and usage. I really wouldn't want to lose that functionality for this, particularly when a simple software toggle is more flexible long term anyway.
9 times out of 10 I am going to use the same charge mode at the same physical location (e.g. at home, slow, at work fast). That would be the real killer feature, geo-fenced software toggle that knows where I am and what mode I previously used here.
It’s a good point. Maybe I just really miss the little green or orange light on the MagSafe chargers. Then it was just a case of picking up the laptop and going, now I have to open it, give it a second to refresh its status, just to check. I’ve left the house a couple times with a dead laptop since getting the newer machine. Sorry for conflating two issues because I still wouldn’t know if the battery is full or not just from the different port.
I don't think the ability to signal users from across the room is a use-case that Apple is designing for, or one they would ever consider. And even if it was, this metric is likely not high priority.
Design continuity is often more important for usability than the number of features, and Apple especially priorities this.
Even if you're going to do this it's far better to be a toggle on software rather than tying it to the port you're using.