Yes well I think so after the ethereum fork your amount of ethereum would still be intact but you would be airdrop the new altcoin
There is no new altcoin. The upcoming Ethereum fork (Constantinople) is an upgrade only, not a split in to a new coin. It plans to implement 5 Ethereum Improvement Proposals (EIPs). The upgrade aims to (very simply) make several things you can do with Ethereum more efficient and therefore cost less fees, and also continues the progress towards Proof of Stake.
You don't have to do anything with your Ethereum, regardless of where it is stored.
You can read more about the upgrade here:
https://github.com/ethereum/pm/wiki/Constantinople-Progress-Tracker