I have a friend at work who is retiring as of this Friday. Based on what I know of her, it seems like some reminiscing of their years of service is a good thing (funny stories and so on). BUT almost more important, I think, is to celebrate and encourage their next adventure. Activities or gifts that encourage and support their explorations of the world that awaits them.
If they have worked 30 years in the same place, there may be a lot of anxiety about their future, and what to do with themselves. So I would think gifts and so on might include stuff about activities they can enjoy now that they are retiring.
Just my two cents. Thanks.