Some people think it is unnecessary to give gifts, because this kind of treat is to celebrate getting a pension, not to celebrate other happy events. Moreover, the original intention of treating guests is to let everyone sit together and talk about the past, or bid farewell to decades of busyness, rather than let everyone give him gifts.
On the other hand, some people think that gifts should be given. They think it is a kind of etiquette to show respect and blessing to each other. They suggest that you can give some simple gifts, such as fruit or flowers, to avoid making a slip of the tongue.
Generally speaking, whether to give a gift depends on personal opinions and cultural habits. If the guests have no special requirements, they can decide whether to give gifts according to their own ideas and circumstances.