There is always speculation as to whether or not a given army will receive new models. For the Skaven, this question comes up frequently. The most recent release of Skaven models was in 2016, so it's been a few years since we've seen anything new from them. However, there are several factors that suggest that the Skaven are due for some new releases in the near future.
First, Warhammer Underworlds: Shadespire was released in 2017 and included several new Skaven miniatures. This suggests that Games Workshop still has interest in producing Skaven models. Second, the age of the current Skaven models is also a factor to consider. The majority of the current Skaven range was released in 2010 or earlier, with only a handful of newer releases sprinkled throughout the past few years. Given that many other armies have received multiple waves of new models over the past decade, it stands to reason that the Skaven will eventually get their turn as well.
Of course, all of this is purely speculation at this point. There is no guarantee that we will see any new Skaven models anytime soon. However, based on recent trends and existing model ranges, it seems likely that we'll see something from them sooner rather than later.