Eventually we'd like to move towards more self-contained templates, but for now we should at least try to render the content as expected, even if that content remains uneditable for now.
Test cases:
{| |{{echo|{{!}} Foo}} |{{echo|style="color: red" {{!}} Bar}} |}
Foo is bug 50589, while Bar is bug 50366.
Version: unspecified
Severity: normal