After completing today's challenge, there is no option to redeem the 100g reward. Are the rewards now held until the weekly challenge is completed, or is this a bug?

I noticed I got 100 gold as soon as the challenge completed. Maybe the redeems step is not necessary for gold

If so, that's a nice little quality of life improvement. Seems worth putting in the patch notes!

I noticed the same thing.  I knocked out two dailies back-to-back and the gold was awarded in the middle of each game.

 

The "Redeem" function will probably be reserved for weekly challenges or more complicated reward chains.

The gold is auto granted upon completion for this.