Both this year and last year, Game of Thrones
had enough nominations to make the ballot in either the Short Form or the Long Form category. I don't know who makes the final call as to which, or if it varies from year to year based on what the award administrators decide; this year's statistics say "nomination declined" under Long Form, which suggests that it was someone from the show, while last year's say only "Ineligible" under Short Form. If the producers did decide, I would agree they were thinking strategically both times-- nothing was going to beat Neil Gaiman + Doctor Who
last year, and nothing was going to beat Joss Whedon + Marvel blockbuster this year.