There is no automatic output because running your code in Python translates into executing
exec(code)
in Sage, which does not return anything and so there is nothing to display. Although if you include print(...) inside of your code, you will get the output. Other languages are executed as
print(language.eval("code"))
so typically you see the last value automatically.
As far as I can tell, this is not a new behaviour, so nothing is "broken". Either nobody has used this language, or they were happy with how it works, or they suffered silently. It does seem inconsistent with other languages, but at this point I am not eager to change anything for historical reasons. It is also not immediately clear to me what the replacement code must be.
Thank you for pointing this out!
Andrey