Not necessarily! We may need some clarification (or a screenshot) though... here are my thoughts based on what you said:
Creative Cloud allows you to keep prior versions if you want. It sounds like you may have this setting activated. Also, keep in mind that the old Lightroom is now Lightroom Classic and the new Lightroom is Lightroom CC. Perhaps you just have both Lightroom CC and Lightroom Classic now. They are pretty different from one another! Hopefully this helps
It may have just been an accidental click If you don't need it, you can most certainly delete it!