I agree with the majority of other posters who suggest you leave anything left to those who contact you, plus, perhaps, a donation to a charity. You could, of course, leave those who don’t keep in touch a token gift if that would make you feel more comfortable, but to be honest, it sounds as if they are getting on with their lives without including you in any way, so I think you have every right to do the same.
However, do enjoy your money whilst you are here, don’t stint. If any is left, all well and good, but really, enjoy your money while you can, don’t feel you have to save it for someone else to spend at a future date.