Season Finale Alert (IT IS POSSIBLE)
I believe there is some data available that could be used to detect at least a "Possible Season Finale" and send that notification out to users that want this feature. You could label it a BETA FEATURE and you could even crowdsource it (have users confirm it is a season finale). Even if you send the notification out, two weeks after the season finale happened, it is still useful information to me and to many other users that like binge-watching seasons. PLEASE PLEASE PLEASE

Could be an option if crowdsourced, but there is no reliable automated way to get this info yet.
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stephane clavel commented
and for people who end up on this page by google search, and are also looking for such a feature, until it's implemented in trakt (and I'd much rather have this in trakt), at least for now rotten tomatoes has it: https://editorial.rottentomatoes.com/article/2018-tv-finale-dates-calendar/2/
-- note to admins: feel free to delete this comment if you feel it's inappropriate to be posted here, I just thought it would help others looking for this option, for now --
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stephane clavel commented
Apparently nowadays (in 2018), most series publish their full schedule (I don't know where trakt.tv is getting the info, but on most seasons that are in progress we can see the future airing date until the last episode on trakt.tv already).
So it should be even easier today to implement this feature.And I'm sure there are many of us who only binge their shows (I don't know how people can stand to wait one week between episodes).
So it would indeed be very useful to receive notifications when a show for which we already watched some past seasons, just finished a new season.
Or also to be able to see a list of the new shows that already finished their first season. -
Gio commented
Thanks for considering this feature. Here are some ideas and excuse my writing in advance since I'm not native English speaker.
The first thing I would do is to aggregate/analyze all past tv shows for frequency and time gaps consistency between episodes, the consistency of the number of episodes between seasons, the singularity of mid-season breaks. If this analysis returns that most shows are consistent by at least 90%, I would say it is worth the effort to implement a little A.I. to figure out season finales and issue a "Posible Season Finale Detected" alert to users, and here is hoping you would agree :)
I'm not really interested in a prediction of season finales, even though some insight into a show's previous seasons and the occasional forecasted air-time presented by TheTVDB could help in that regard, the best feature, in my opinion, is the alert after the final episode has aired, even if it is after a couple weeks (when a bigger gap was detected than the usual show frequency), even if the alert is wrong 10% of the time, it is still a great tool.