Updated artwork?

Fall is the time when many shows return, and with them usually comes new artwork in the form of posters and title cards promoting the new season.

This year, I've noticed that oddly only some returning fall shows have been updated with new artwork on Tivo/Tivo Online while others have either remained the same or in some cases been stripped of the image entirely.

New artwork:
How to Get Away With Murder (ABC)
Flash (CW)
Grimm (NBC) [even though its returning in Jan]
Quantico (ABC)
blackish (ABC)
Life in Pieces (CBS)
The Real O'Neals (ABC)


Old artwork:
Grey's Anatomy (ABC)
Arrow (CW)
Shameless (Showtime)
Gotham (FOX) [still shows last year's "Wrath of the Villains" subtitle]
Blindspot (ABC)


Deleted/generic placeholder:
The Celebrity Apprentice (NBC)
Girls (HBO)
Silicon Valley (HBO)
The Affair (Showtime)
Shadowhunters (ABC Family)


I'm wondering what's going on and why only a handful of shows have been updated this year. Does this have something to do with Rovi guide data?

I realize that Tivo has more pressing concerns at the moment fixing line up issues and messed up One Passes, but you would think that in that case none of the artwork would have been updated so far.

Maybe its just me but I always look forward to the new artwork. It gets me psyched for the upcoming season.