I really don’t see the issue.
Yes it’s a bit of a mess that the units have too much first, primarily the 8-car units, however I can’t see what the issue is with the solution.
If someone is “confused”, then don’t sit there, there’s plenty of other carriages to use. If they don’t know, then they’re none the wiser. If you are in the know, then it’s one of those few things in life where you can get a small token upgrade for free.
I tend to agree with the view that the people fussing about this are those who have fully knowingly tried it on using the front section and got caught out, or were none the wiser at all and just placed themselves in first and again got caught out.
Having said all this, it would probably be better if the whole train was laid out as first is, and actual first just ditched. Someone is going to appear here and say that would cost too much now…