How does Eric Hill keep writing new Spot books when he's been dead for 9 years?

Eric Hill died in 2014. I haven't done an exact count, but there have been at least 30 books in the Spot series released since his death. Every single book is attributed to him.

This Penguin Random House page on the series is surreal.

I hate that they do it this way, because Hill's Spot books are very cute, but the new ones are miserably soulless. Does this happen a lot? I know they're still churning out Curious Georges and Cat in the Hats, but they attribute those to the new author (or at least don't claim Rey/Seuss wrote them).