The breaking change that you are in favour is to change the behaviour of a whole established rule (code spans backsticks, HTML inline, labels in links…etc. don’t require a specific escape for |) just because one extension may require to parse the |, and you prefer to change this rule (which is a general end-user rule) rather than an implementation detail (inline parsing should be after block parsing, or inline parsing should not modify block structure, does the end-user really care about this?)
It is fine to look for making life easier for developers, but end-user experience and requirements usually come with a higher priority… So yes, we have more generally a different perspective on software development here