I always thought a 1 year post doc was a waste of time until I said this to a well respected and successful professor with a lot of experience with post docs and she said that sometimes post docs are only a year as at first especially if the PI doesn't know the person. So the year will be a chance to show your skills and demonstrate that you're suitable to the role/research. Basically for some PIs they strategically only state it's 1 year, then they'll extend later on.
But of course there will be those post docs that are definitely only 1 year due to requirements/funding restrictions.
I would say go for it. It's experience at the end of the day. And any post doc is hard to get, so congratulate yourself and grab it with both hands :)