It's also not unprecedented, fortunately, since low level roulette gives exp that grows for each level (which would equate to rank in PVP), and when you get to level 50 you get a special currency reward in lieu of the experience bonus.

As for the bonus being large and equal for everyone as mentioned 2 posts up- I think it would make sense for it to scale with each rank, same as it does in the challenge log (and same as low level roulette does). With each rank the amount of exp needed to level up increases significantly, and whereas I remember gaining a few levels a day, and then a few levels a week, early on since the amount you get from a single match is independent of rank and more significant at lower ranks, at higher ranks it seems like it took like a week or more to gain a rank. So having a large fixed amount might give a big boost early on, but it would become less and less worthwhile the higher someone was ranked- so like a diminishing returns situation. And giving people a daily exp bonus at level 15 the same amount that people would be given at, say level 40, would be disproportionate one way or another.