That is most likely true, yes. It won't quite be the same, no matter what is done to make a new Penny. It won't be the Penny of Academy days, and that's a shame. Not that it would stop Ruby from trying to be her friend again, of course! Theln again, the good Professor might have a memory backup chip to install, because RWBY honors anime tropes & why should Science! bow to your well-reasoned argument? Not saying you're wrong, mind you, but there's ways to have Penny back as is/was if the story demands it. Then again, RWBY as a story is big on actions having consequences down the line, so a shiny new Penny may likely not be the Penny we knew. Cue the angst!