As far as the original Ghostbusters universe is concerned, and if you don’t count other media material (like the 2009 video game), we haven’t seen individuals hunting down supernatural entities since 1989’s Ghostbusters II.
If this Ghostbusters trailer is indeed hinting at the plot and not simply a video meant to get fans excited, then it indicates that the Ghostbusters team has been inactive for a long time.
Of course, we saw a new team of Ghostbusters active in the present day just a few years ago, but that was in a different universe.
Whatever’s this next Ghostbusters movie ends up being about, presumably there will be some mention of what’s happened in the three decades since we last saw Peter Venkman, Ray Stantz, Egon Spengler and Winston Zeddemore.