Others colleagues would also usually organise a virtual envelope with money inside to wish you farewell.
I find it hard to imagine you have no such contact at all, or that you would say nothing in those meets. You are planning work every now and then, aren't you?
In the past, I've tried to give key people on longer-term projects I'm working on a heads-up. But I trusted them and it was longer-term. At the end of the day, I'm not going to let the word out before I'm ready if I'm worried it has the potential to bite me financially, e.g. because of vesting.