For example, if bitcoin is going to crash and I exchanged it into $1200 Ethereum lets say. And it goes down to $800 USD, will the Ethereum value go down?

Could you exchange your bitcoin into another currency to be protected from a crash?
I think Coins like Doge, LTC , USDCOIN all of these are 99.9% stable always in the same price, 0.01% prob that you are very very very unlucky and it drop when you buy but I don't think it will happen.

What do you think ?