In the countries you mention, this was pro-national propaganda, perhaps. Certainly not pro-government. Because the ruling parties could change every 3-5 years (as mentioned above).
Also, there is considerable public discourse in these, and any comparable countries, that discuss alternate or dissenting points of view. In some places, the primary school takes on history are now very critical of the formative years of the nation (which I don't necessarily agree is a useful thing even for the indigenous people of those countries, but it certainly is a thing).
I'm not aware that anthem or flag ceremonies are a regular part of school life in these countries either. Perhaps 40 years ago. I was just talking to someone the other day, who grew up in Washington in the 80s as an immigrant and I asked him about the anthem (which it seems nobody knows the words to anyway). He mentioned that one single high school teacher had them recite the Pledge of Allegiance, which at the time he found very annoying. Every other class ignored it, so it was just a case of one nutty teacher and not an institutionalised pattern.
So whilst I appreciate your earnest intent towards discourse, I think that what you are suggesting as comparisons are totally off base- either rooted in experiences decades out of date, or false equivalences.
Whilst this is a noble sounding sentiment, in my mind it veers perilously close to the "just asking questions" line from people such as Joe Rogan. There is trying to be unbiased, and there is comparing apples to oranges and deciding that they are wheelbarrows.