Hi - this may seem like a silly question. I have always just booked Main Cabin seats (PP, and now EXP) which are obviously more expensive than Basic Economy seats, but in essence - do I need to be doing that? If I book a basic economy ticket - I still get Main Cabin Plus seats free. So what is the downside?

Thank you for indulging me! I tried to search the forum but couldn't find anything.

I may have figured it out. No possible upgrade if I book basic economy.... right?