The actress said she expects fans of the HBO series to be equally blindsided by her departure, as Irri is still alive in the original George RR Martin novels.
"I was surprised reading Irri's death," she told TV Guide. "In the books, that doesn't happen.
"In the books, something kinky happens with Irri. So I think lots of fans will be disappointed. It's a little bit of a relief for me though."
She continued: "I will miss being part of something so epic. [Game of Thrones is] the kind of thing I'd watch, that I'd like to just be a part of that big buzz as well."
Acharia also admitted that she enjoyed the "meaty" scene earlier this season in which Irri discovers her lover Rakharo (Elyes Gabel) is dead.
"I felt for Irri. I think it sucks to be stuck in a desert and then all of a sudden the dude you fancy and never told is dead and you find his head."
Game of Thrones executive producer DB Weiss recently said that the show will stray from its source material on occasion.
"Sometimes it's a confidence to violate the letter of the books to do better service to the spirit of the books," he said.
"I do think it really is about just being willing to take the risks that are necessary to do justice to the show as a show."
Game of Thrones currently airs Sundays at 9pm on HBO and Mondays at 9pm on Sky Atlantic.
Watch cast members discuss season two of the show below: