well you'll find you probably have grown apart and changed but no big deal, if you were close, why not give it a go.
I recently got back in touch with a guy I knew about 20 years ago (and was a groomsman at his wedding). A guy we used to work with back in the day had died and I got in touch to find out how he died.
We had a lot of catching up to do and have spoken a bit. It's not the same though. We have changed a lot and we tend to argue a bit, mainly due to politics, of which we are polar opposites, and he likes an argument. So we don't have a lot to do with each other since the catch up calls. It's now a short text or comedy meme here and there and that's it.
I think I broke his heart when I told him I don't like Tool anymore ha ha
I don't regret doing it though, at least you'll know and it could reignite a great friendship.
I've thought of getting in touch with a friend from 10 years ago who I wiped due to some reasons I felt strongly about. Not sure if I'll do it or not.