Modern MX stipulates that you must have a return spring.
VMX stipulates that the pegs must return by themselves.
So you don't need springs, although certain clubs/scrutineers might want them.
Same story for handlebar cross brace pads and folding tips on gear-levers.
Despite the talk about rules on these forums, its VERY rare for people to be told to go home over minor stuff like this - particularly at Club level.
At very worst, some rubber bands made from inner tubes, a couple of cable ties and a few minutes will pacify even the most 'difficult' scrutineer.