although it has NOT yet been officially announced by Emmerdale it does look as though ...
Mike Parr{RossBarton} is leaving Emmerdale at some point in 2018 as he has been announced for movie ''Dark Ascension'' playing the character role of ''G'' according to his IMDb Page
http://www.imdb.com/name/nm3477466/ the filming of the movie has been put on hold until 2018 according to the movie's IMDB page
http://www.imdb.com/title/tt1643249/?ref_=nm_flmg_act_1
Anthony Quinlan{Pete Barton} is also rumoured to be leaving Emmerdale at some point in 2018 as he has also been announced for movie ''Jessica Frost'' playing the character role of ''Cutter'' according to his IMDb Page
http://www.imdb.com/name/nm2052712/?ref_=nv_sr_1 , the movie currently is in Pre-Production according to the movie's IMDb page
http://www.imdb.com/title/tt4519000/?ref_=nm_flmg_act_1
we already know that Gillian Kearney{Emma Barton} is being killed off and will be exiting Emmerdale at some point by December 2017{as confirmed by her at The Soap Awards} and someone on twitter which the tweet was posted to Digital Spy Forums which I can't find said tweet anymore that the person
https://twitter.com/MartinGregory who posted said tweet said ''he was told by a certain funeral company in Yorkshire that they were filming Joe Gill's character ''Finn Barton'' funeral a couple of weeks ago at a cemetary outside of the one they use in the village.'' but he has since DELETED said tweet