In most cases it would not matter if the site was hacked and whatever personal information you have was captured. An anonymous site where there is no financial interest should not be an issue.

But if the site is hacked they will probably capture the whole membership list with whatever personal data you have. I just had a look and what appears to be a valid date of birth is showing on your profile but without your full name. You may think that is safe, but if the site is hacked the hackers may have access to data from another hacked site which they can match using your email address. If that other site has your real name, and this has your date of birth, it could bring them one step closer to identity theft or convincing some authority that they are you.

But there is another reason why hackers may bother with this site. If actual passwords are stored, just maybe you have used the same password at a different site where there is financial value.

That happened to me. A low budget site was hacked and I had used the same password at a handful of others, including Paypal. So they were successful in getting into Paypal, and changed some things, preparing to spend my money. Fortunately, Paypal sent a notifier of the changes and I was on top of it before any damage was done. Had I not been quick to see that notification it may have been a different story.

Back to your original question. I don't see the need to change your password .... unless that same password is used at other sites.