Policy on reviews for series

What is IMDb's policy on reviews for series that have not yet ended their run? When can one submit a user review for a series where not all episodes have been shown yet? I ask because the guide (https://help.imdb.com/article/contribution/contribution-information/user-review-guidelines/GABTWSNLDNFLPRRH?ref_=helpms_helpart_inline#) doesn't say anything at all about series in particular. For example, I noticed there are several reviews for Game of Thrones written at a time when only the first episode of the first season was available (https://www.imdb.com/title/tt0944947/reviews?sort=submissionDate&dir=asc&ratingFilter=0). I feel these shouldn't have been accepted in the first place but on the other hand I'm not sure where one should draw line because I also understand that blocking user reviews for all series that have not yet ended their run might not be considered the best option.

That said, I do think there should be something in the guide about it. Perhaps it would be a good idea to at least point out that reviews can also be written for individual episodes. Also, I think it would be good that if one starts writing a review for a series, one has to choose which season(s) they are writing about. This text would then appear, for example, next to the review date. Ideally, readers could use this information to sort reviews as well.