99% sure it was a Saikyo blog update or Ayano interview where he stated delayed wakeup was the mechanic for advanced players, while RFC was in place (in part- you're absolutely correct about it also helping charge/grapple characters) as a mechanic less experienced ones could use.I've seen you say several times that Capcom introduced RFC to help ease of execution for Ultras.
I would like to see a quote or something alluding to this because from everything I've seen RFC was implemented to open up new combo possibilities. Namely giving the charge characters a way to land their ultras and the grapplers. Nothing to do with execution.
I remember it because I thought at the time "Oh, that's me!" - as when I tried out the USF4 fan-made PC patch, I was able to actually use Ultras outside of wake-up/neutral since I didn't have to FADC into them.
And as I was about to post did one last search- here you go: http://www.siliconera.com/2014/04/15/capcom-says-ultra-street-fighter-ivs-red-focus-meant-casual-players/