I really don’t want to get my hopes up for a let down later on but I thought I’d ask.
I’ve been contacted by my regional counselor who said she “loved my essays” and asked me to send in a published piece of writing and an additional letter of recommendation. Is this just a regular display of interest, or could it be indicative of a possible waitlist/acceptance?
Also I’m really crushed after my ED2 rejection so I may be pathetically grasping for straws @ other colleges. Forgive me 
Yes, I would say its a very good sign! I don’t think AO would have contacted you for additional info if she/he had no intention of advocating your candidacy in the whole committee. Chances are AO is trying to substantiate his/her case for your admission. It used to be extremely rare that applicants get contacted by AOs, but in this admission cycle I have already seen two cases in my area where Harvard AO reached out to applicants with extra requests. Both were accepted REA. I know this because one of them was my DD. Best of luck!
I’m with @jzducol. Best of luck! 
This also occurred for our daughter four years ago. She is now a Senior at Harvard.
Best Wishes!
Generally speaking, being contacted directly by an admissions officer for something specific like a writing sample or more information for one of your prizes, pieces of writing, etc. - is definitely a good sign. I agree with @jzducol, I suspect they may have requested the writing piece and LOR because they’d like to flesh out your story more before they present you at committee meetings - which would suggest you’re definitely “in the running” so to speak. If you weren’t, they wouldn’t be so interested.
I know one person in my grade at Harvard who was similarly contacted by an AO - he had mentioned a piece of poetry he had written that won several major prizes and was later published, and was asked by the AO to send it in for consideration along with more details - and obviously was later accepted.
@jzducol @ChezCurie @GreatKid @Telluric Thank you for your replies! It really eases my mind. That being said, is /not/ being reached out to by an AO a bad sign? If this is perhaps evidence of a acceptance, could lack of of communication from other schools show disinterest and be predictive of rejection if they are on the same caliber as H?
No. For the vast majority of candidates at any college, the AO has everything s/he needs to make a decision.
I don’t think that the absence of such a contact means anything at all, but the presence of a contact like that is a positive. You have managed to convert a positive thing (Harvard contact) to a negative (no contact from other schools) in a way no one would ever think of. Maybe try not to overthink things!
I was never contacted by an AO and was accepted SCEA. He did send a letter later describing how much he enjoyed my essays though. Best of luck!
What about for math summer camps? My AO contacted everyone who went to a relatively selective math camp (PROMYS, SUMAC, HCSSiM) for some sort of portfolio. Would this be a positive or does this just seem like a regular thing they do for such students?