It's great to celebrate AA milestones and anniversaries.
But I have always been advised to mention it only in passing or discreetly when invited.
Some other tips I have been given:
Don't celebrate in advance: keep my mouth shut until the day.
Mention it once then let it go: don't keep celebrating it over and over or at lots of different meetings.
It's very joyous, of course, to celebrate milestones and anniversaries in meetings, but the focus, in accordance with Traditions I, V, and XII, should be on carrying the message, not celebrating the individual: in reality, what we should be celebrating is what God has done. The danger is that the whole meeting becomes about singling out the individual.
We're the 'done to' and the 'done through', not the doers: our action merely permits the Doer to do.
In encouraging people to share on their birthdays, groups sometimes ask someone to say, 'How they did it'. Now, of course, action is necessary, but it is the Higher Power who does the heavy lifting. It might be more helpful to ask, 'How did you establish a relationship with a Higher Power who did for you what you could not do for yourself?'
There is a danger that the attainment of milestones plus the celebration thereof becomes an objective in itself, and that the achievement is seen as the personal achievement of the individual (which at the same time encourages viewing relapse as the personal failure of the individual). I'm sceptical about how healthy this is for the individual or the group.