Yes BQX is ETHOS. Ethos was originally called bitquence and traded as BQX. Then the Ethos rebrand happened in Nov 2017.
This has left a fair amount of confusion about BQX and ETHOS But they are the same thing.
People who bought BQX in the ICO or have bought BQX since you can see it is the same contract address as ETHOS so basically is just a name change.
You do not need to change anything in MEW or your hardware wallet. You can check your wallet address on Etherscan and it will show the tokens as Ethos and the price in USD$. These will all change to display Ethos over time and you don’t need to do anything.
Also if you are buying or selling – BQX still shows on Etherdelta and Binance. You can still buy & sell BQX on these exchanges and you are buying Ethos.