Is there any reason to believe FP is the "new hotness". Each year in the Stack overflow language trends report the FP languages are barely making an impact.
FP languages are not that big. FP architecture and practices are very popular. React, Immutability and more have become mainstream.
A recent example is SwiftUI. While Swift is not a FP language, SwiftUI (FP UI framework) and Combine (a FP toolkit) is being pushed by Apple as the future UI architecture for all its OSes.
It's the new hotness if you measure hotness by the amount of Medium posts written about it.
I don't know if you have noticed, but FP is not "new" anymore. Almost every programming language today either has some FP-flavored features or keeps adding them. And there are plenty of good reasons why many [smart] programmers think that OOP has failed.
Complex static type systems on the other hand - are kinda "new kid on the block". And if we are not careful that may become a "new OOP" - doctrine so complex and convoluted that could become an impediment in building software. I know, static type systems are cool and all but it's easy to get from something elegant and simple like Elm into say Haskell, Idris, Agda etc. and into the weeds of homotopy type theory.
Funny that. While I prefer FP, and did since I've learned Python, my teachers are really hot about OO, even pushing us to use it in Python projects.
(Looking at projects from previous years, they mostly seemed to use Java. Then also because of browser integration and obviously because of the OO <-> UML <-> Project links ?)