Now this is getting confusing ! It’s true, no it isn’t true, yes it is true.
It’s not confusing at all. This Synod has no doctrinal authority. It is advisory only (to the Pope). The Synod cannot define doctrine (truth).
It is an assembly of diverse theologians discussing topics relevant to the modern Church. Not all theologians will agree on all points, and they never have (the Early Fathers hotly disputed many issues that are now settled Doctrine, including Baptism by heretics. Canonized Saints have vehemently disagreed about unsettled Doctrine (at the time) such as this).
That’s normal, and it is to be expected. The purpose of the Synod is NOT to teach doctrine. It is to
advise the Pope ONLY. The Pope is free to accept or reject the advise.
It is natural and normal that participants who do not agree with the Synod’s recommendations submit a dissent brief, explaining their objections and the underlying rationale. This is common in any system of fair and open jurisprudence - for example, in the US Supreme Court, which almost always issues a dissent finding for any non-unanimous ruling.
The thing that I find surprising is that
ONLY 13 Cardinals raised an objection. That’s a very small minority of the Synod participants. It is MUCH less than a 1/9 minority of the US Supreme Court Justices.