To be honest yes.
125 > 120 days Concierge guests make requests.
120 Platinum.
105 days Gold.
90 days silver.
Then 75 days new cruisers ( non concierge)
The Cabanas at castaway often have gone by 00.01 120 days.
Palo Brunch, Remy highly sort after. Often sell out fast.
Spa ( formal night, afternoon slots) and any shore trip with dolphins, animals like horses, sell out.
Boutiques appointments.
Special early flights in Alaska.
Palo dinner.
Various shore trips like St Petersburg where people can't go DIY.
Now this is an indication what normally goes. Each cruise can be different, but the most popular stuff can sell out.
Tips, for things like Palo request as soon as you get on in the location advertised in the welcome onboard navigator, and keep asking as people can cancel.