You don't say where you live so now we have to guess.
The main reason for changing is the condensation that will be in the forks a long with your riding.
If your in cold country and do a lot of dirt roads then yes do it in the spring so it fresh for the coming summer months. If your in the south you could go another ten thousand.
Vic has us change things cause they don't know them selves how far to go or where and how we ride.
Belts are good for 70 thousand and break fluid is good for 4 to five years. Its all a judgment call on the riders part. For sure if you ask dealer they tell you now cause of the money they will make off you.
Order some seals and put on the shelf so when you need them you'll have them.
Please add your state and model of bike you have. Click user CP @ top of page and then far left click edit signature. Thanks