Is HOFAS the last book in the series? Thoughts?

HOFAS very much felt like a finale to me however, there are two things that are bothering me. The first is that it would be very natural to type a fourth book called the house of many waters, but I don’t really see where they’re gonna go from here unless they just go into rebuilding the world and kind of do a Court of silver flames situation with a side plot. There is also the option of having more crossover plot lines, but what do you think?