Not a lot of time is spent focussing on Hogwarts during the seventh book, but I was wondering if there was any evidence of there being any Quidditch taking place during the time the trio were hunting for horcruxes?
There were still the four houses, and the Quidditch pitches were still standing until the Battle of Hogwarts (when they were destroyed by Death Eaters), but it seems unlikely the Death Eaters would want Slytherin to look bad if they lost.
Unknown.
There is no mention of Quidditch in Deathly Hallows that might refer to the inter-house Quidditch Cup. I am also unaware of any J.K. Rowling interview which touches upon this point.
If I had to guess, I would probably guess that it didn’t take place. We know that Snape is a double agent, trying to keep the students safe from the Carrows:
[Dumbledore said] “I am counting upon you to remain in Lord Voldemort’s good books as long as possible, or Hogwarts will be left to the mercy of the Carrows….”
— Deathly Hallows, chapter 33 (The Prince’s Tale)
Quidditch is an immensely dangerous sport, and there’s plenty of scope for an “accident” to occur to somebody on the pitch, whether at the hands of a student or one of the Carrows. He’d be expected to join in the student-baiting, so no counter-courses or spells for him. Then consider that Quidditch players are fairly high-profile students, and come in for a fair amount of flak, and you see why Snape might be reluctant to allow Quidditch games to run.
There are plenty of plausible cover stories:
You can imagine the Carrows would happily go along with several of those.
