As much as I don't like limitations, I do support the idea of a few for a photo contest.
I really like the idea of concurrent exhibition threads to share and see contest-worthy photos that don't fit within the rules.
i.e. I'd love to see a fantastic 10yo picture featuring someone's barn with a beautiful sunset behind it, some striking plants around it, and a handsome goat trying to eat them
seriously! That's good stuff
And yes, a nice photo is a nice photo and worthy of placing in a contest no matter when it was taken. If we only had the one contest it really wouldn't matter.
Looking ahead though, if the goal is to have an annual photo contest, I agree it would be wise to limit the entries by some measure of "current" like this season's photos. I can see that it could matter --if the same great 'old' photos were submitted every year, or if entries had to be restricted because Sue's old picture of Zuzu's rose kept winning every year...stuff like that.
Also, an annual contest requiring current photos would necessarily stimulate the taking of fresh photos which is fun to do and I would think good for the site.