Do I have this right? A db plan that permits continued participation after normal retirement date must provide participants with a benefit equal to the greater of: (1) the age/service benefit or (2) the actuarially increased value of the normal retirement benefit when the participant ultimately retires, unless the plan provides participants a suspension of benefits notice at age 65, in which case the plan need only provide the age/service benefit. Also, if a plan opts to provide the notice, does the plan need to contain a statement that such a notice will be issued?

I think you have it right, and I believe that the plan would have to contain a provision (including mention of the notice) if you were going to suspend actuarially equivalent increases.

I agree

But, the notice will only result in suspension if the person works over a certain number of hours per month or year, 48 per month or 480 per year if I recall correctly.