Order changes in PG16 since ICU introduction

A couple of days ago, our PostGIS PG16 bots started failing with order
changes in text.
We have our tests set to locale=c

It seems since April 20th, our tests that rely on sorting characters
changed.
As noted in this ticket:

https://trac.osgeo.org/postgis/ticket/5375

I'm assuming it's result of icu change:
https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=fcb21b3ac
dcb9a60313325618fd7080aa36f1626

I suspect all our bots are compiling with icu enabled. But I haven't
confirmed.

I'm assuming this is an expected change in behavior, but just want to
confirm.

Thanks,
Regina