Quality forks will have maintenance schedules specified by the manufacturer or brand. The most frequent maintenance is probably changing the bath oil, which is a small amount of ail that sloshes around in the fork legs to lubricate bushings. There is sometimes damper oil to be changed less frequently, and I believe some of my air forks have small amounts of oil dropped into their air chambers.
I've not found a few months of sitting around to be a problem. I suppose after some long enough period of time that something might deteriorate.
Those rubber seals do deteriorate with time and sometimes need to be replaced. I just helped a friend replace his -- on a five-year-old bike -- this spring.
What brand and model fork do you have on your bike?
There's a statement on Page 5 about service intervals. Changing the bath oil in the fork legs is recommended after every 50 hours of riding. Your bushings will last longer if you do that and keep them properly lubricated.