The tonal center collapse is done purely vocally in an a cappella
passage and when the instruments come back in, it's in a resurrection
key and instrument groups (like brass) that are typical for it.
[...]
Here is a link <https://www.youtube.com/watch?v=ixFCKKIMvkk> to a
Herreweghe version. The piano extract displayed in parallel would
suggest that there is, after all, an instrumental part even in the 2:30
and finally 3:00 (or so) locations which is a bit surprising to me since
I remember how we fought keeping the intonation in line so that the
resurrection trumpets could fall right in. I cannot hear instruments
there right now but I have only builtin speakers at low volume right now
so I may be wrong about that.