Honestly my experience booking at 7-months was kind of a roller coaster. I assumed I'd be able to get an Island Garden or Pool Garden super easy, and thought I'd have no chance at Standard. I also decided against walking.
On the 7-month day, only Ocean View was available. And then after a day had passed, even that became booked up. Granted, we were booking a 2-bedroom and there are fewer of those than studios, but I was still flabbergasted. Weirdly, the previous week had availability for a 2-bedroom in a Pool Garden view, so I snagged that. I put in a waitlist for the real days I wanted, and after 3-4 weeks, the waitlist came through.
My best guess is that at the 7-month mark, people (walkers?) snagged up the availability, and I had to wait for them to finish walking before my dates reopened up, which is why I was able to get a week BEFORE my intended dates but not the actual dates I wanted at the 7-month mark.