So, this is actually something that we were very concerned about during the game design process as well, as robustness and consistency between events is key for a dynamic field element like this. So, we built a test bed out of VEX IQ parts.
This tester ran for about 3 weeks continuously, stopping only for battery changes, for a total of ~10,000 toggles. The detent and pointer were definitely a bit rounded down at the end of this test, but still functional, and in our testing we have never seen a pointer break or snap off.
It's tough to estimate how many matches are represented by 10,000 toggles, as it will depend on the competitiveness of teams playing at the event, and this post should not be used as a formal load rating guarantee. But, I would be comfortable in saying that it probably represents at least 15-20 competitive events, probably more.
That all said, if you do happen to have a very competitive series of events, or start to see excessive wear, each Flag is reversible - there is a pointer at the top and the bottom, and the bracket with the detent has an additional one on the back as well (see attached image for the reversible pointers). This doubles the lifetime of a given Flag/Detent from (my very rough estimate of) 15-20 events to 30-40 events. EP's running multiple events can also rotate their Flag positions during setup to distribute the load more evenly, as the bottom row is likely to see more engagement match-to-match than the top two rows.