Casascius Coins - will they get obsolete?

[vinaha]

If I have original Casascius coins, will it be possible to redeem them years from now or will the private address at some point become incompatible with the blockchain?

[25hashcoin]

I'd redeem and get rid of the BTC in it ASAP. Eventually it may become worthless as the BTC chain enters a death spiral and you can no longer transact on it.

[DannyHamilton]

If I have original Casascius coins, will it be possible to redeem them years from now

Yes. As long as Bitcoin continues to exist and have value, it would be possible to redeem them.

or will the private address at some point become incompatible with the blockchain?

No.  That's not how bitcoin works.  It cannot become incompatible with the blockchain.

In case you weren't aware...

That Casascius coin has BOTH Bitcoin value AND Bitcoin Cash value.  It can be redeemed for either or both.

(Assuming that the Casascius coin hasn't been compromised and had its private key leaked/stolen.)