Not accurate at all, mindfulness and samadhi are two different factors in the eightfold path

One of the core practices of insight meditation (Vipassana) is to be mindful of your inner thoughts, like through "noting", and observe them through the lenses of the 3 characteristics. You use one-pointedness concentration (Samadhi) to tune into these thoughts. You can also do Samadhi without Vipassana, as many yogis have, but you cannot do Vipassana without a baseline concentration ability. Some people use mindfulness meditation and Vipassana interchangeably, but it is not entirely accurate, yeah. Mindfulness is only one exercise of the broader insight meditation (Vipassana).