Fixes #36096 (closed)
Proposing to revert https://github.com/twbs/bootstrap/commit/db61cf3d6a907756aee2b0c4ee2cb6488c0ed459; probably the safest move here for the v5.2.0.
(Haven't yet looked at the Dark Mode PR but depending on how themes are handled and if dynamic/contextual dark theme are possible, that could help with this definition of .text-muted)
If this PR is merged we could reopen https://github.com/twbs/bootstrap/issues/34457 and try to tackle it for v5.3.0.
Live preview
/cc @mdo