It's interesting stuff (the full paper is here) but extremely conjectural. The scattering of phrases like:
...suggests that the metric will have similar extendibility properties as the scalar field. It is then tempting to conjecture, as was done before in Refs. [6, 23, 24]: if there exists a parameter range for which β > 1/2 then the corresponding (cosmological) BH spacetimes should be extendible beyond
the Cauchy horizon with metric in H1 . Even more strikingly, one may be able to realize some of the previous extensions as weak solutions of the Einstein equations.
This would correspond to a severe failure of SCC, in the presence of a positive cosmological constant!
indicates an utter lack of actual evidence and that the authors are engaging in speculation.
SCC, BTW, is the Strong variant of Penrose's Cosmic Censorship Hypothesis (wiki) and it's disproval would be immensely changing to current models of physics, indicating that events cannot be reliably predicted from starting conditions. Not necessarily a bad thing for time travel...
Time, time,time, see what’s become of me. While I looked around for my possibilities... My AITAS files.