Jbjb is correct. You run a risk with any large chips. I can give you lots of examples. Following the theft at Bellagio of $25,000 chips all of their $25k chips were canceled. Players had six months if I recall to exchange their chips. Players in the poker room had no trouble because they were known. Others did have a problem.
Chips can be canceled immediately and without notice but you have six months to cash or exchange them.
Once the redemption period ends you have a collectible for ebay.
Edited to update:
I checked the NGC regulations. You have 120 days to redeem canceled chips, that's four months and not six.
The casino must post notices that chips have been canceled and they must run ads in two general circulation newspapers. I remember the Bellagio ad in the LVRJ following the craps table theft.