Yes, absolutely correct. Some people are getting too hung up on the word "sequel". Don't think of an ED2 like an entirely new game, but rather a new core engine from the ground up using a lot of the same code for features as the current game and all of it's assets, including the galaxy.
I'm not saying it will certainly happen, but I do think it's a distinct possibity given what Frontier wants to incorporate into the game going forward. Implementing space legs, better networking, better vehicle support, and a stellar forge with far improved planet tech supporting all world types might simply be easier to accomplish by building a new engine from the byte up, instead of trying to shoehorn it all into the current game. They wouldn't be throwing away all of the work up until now, but rather refactoring it into a new engine where they've learned from the mistakes while coding the current one.
It likely isn't the case, but to casually dismiss it like it can't happen isn't realistic either. It happens all the time in the game's industry, because sometimes when improviing a large game with lots of code it's just easier (and faster) to start new code instead.