This gets a big +1 from me too. I've had some great battles, and a lot of the time have wanted to at least be able to say "gg" to show my respect. Other times I've just wanted to say something when others have worked to save me or have just shown real teamwork.
I wonder, given that typing out sentences (or even single words) using a controller during the short podium scene would be rather difficult, would the ability to just use emojis be useful? Maybe there could be an alternative "end of game" emoji wheel available containing the usual "gg", "ez", or whatever people want. This wheel could possibly be customisable with reactions that you can unlock (just like the main wheel), or you could have custom messages that you could configure beforehand. Those you can type in using the on-screen keyboard outside of a match, but are then quickly available during the podium scene on a reactions/messages/emoji wheel.
Any thoughts on this? It would apply more to us console-based players, I guess. It feels like a solid idea, but I'm not sure.