The briefs in FS Credit are full of references to the "bad old days" of the pretextualist era, depicting decades and decades of purposivism as a mere wrongheaded frolic and detour in the history of statutory interpretation. That makes too light of the big question here, namely, what to do when statutes are drafted under one interpretive regime, but litigated under another decades later? That question, in turn, goes to the fundamental matter of how much in conversation we expect the courts and Congress to be. Justice Scalia always assumed his interpretive methods were in conversation with, or at least known to, Congress. The current Court seems to care about this conversation a whole lot less. And it's not an issue confined to the implied-rights-of-action context. It's highly relevant to areas ranging from administrative deference, to severability, to virtually any federal statute drafted before the mid-1990s.
My essay currently up at Scotusblog offers a broader discussion.