Not sure if this is a regression:

% SOF
\nohyphencollapsing

\setuphead[chapter][align={nothyphenated}]

\starttext
  \chapter{Such --- Emdashery}
\stoptext
% EOF

Expected: No collapsed hyphens.

Actual: Hyphens are collapsed.

Workaround: Remove the nothyphenated option or insert \nohyphencollapsing
into the \chapter command.

Is there another way to prevent collapsing hyphens with a single setting
that applies to the entire document?

The hyphens did not collapse in the previous version.

Current version: 2021.05.06