I'm also going to attempt for server first 90 monk, along with pandaren. I sent in a ticket asking about the RaF and SoR just a few days ago:
"I've searched for information on this, but could not find a complete answer. For the server first 90 achievements, will benefiting from the Refer a Friend or Scroll of Resurrection bonuses disable the possibility of earning the server first on that character? The same as server transferring characters within a certain time for server first achievements."
"Greetings,
Thank you for contacting the Game Master department!
In regards to your question, we actually have plans currently to address this concern specifically. They won't actually turn off the Refer a Friend bonuses but our plan for right now is to make it so any character that did benefit from something like RaF is just flagged and not eligible to receive the realm first achievements. Now that could possibly change before MoP hits but what ever happens we will likely have some way of just keeping people from insta leveling to 80 and being eligible to receive it.
Just keep an eye on our forums over the next couple of months. If we do have any updates they will be posted there.
"
So RaF could still change, but I highly doubt achievements will be given to those who use it.