Actually KOST usually goes Christmas within a few days of of the same date every year. This year they went the day before their Disneyland party, last year it was the night of the party and in years past it was the day after, so they really didn't go early, at least not in relation to when they usually do.
As for the music, yes, it's terrible. From what I've heard, this is the second year that corporate programmers have had control of the KOST Christmas playlist. Lot's of repetition, lots of the same song by different artists. Honestly KOST sounded much better when the holiday programming was handled locally. I mean, I didn't like it that much then, but going back to letting the KOST PD do the music would be a vast improvement. Clear Channel, they really are like Kmart, but that's nothing to aspire to.