The precise relationship between The New Batman Adventures (TNBA) and Batman: The Animated Series (BTAS) is frequently a point of contention among viewers, who often disagree over its canonical status. At first glance, the two seem linked: both feature DC‘s Gothams Dark Knight, many of the same villains, and the same production team. However, significant differences in tone, animation style, and narrative focus have led to some questioning whether TNBA should be considered a true continuation of BTAS or a completely separate animated Batman series.
https://screenrant.com/the-new-batman-adventures-animated-series-part-sequel-continuation/