Everything that was de fide before Vatican II is de fide today, and nothing has been proposed as de fide since Vatican II that was not already de fide before the Council. What that means is that the faith taught by the Church has not changed.

The Church is more than just doctrine. It is well known that most Modernists in Pope St Pius X's days started their plotting in the liturgical area, which is the PRACTICAL application of doctrine. The V2 anti-church has corrupted people's application/attitude/practices of the Faith, even if the core tenants of the Faith are still "pure".
Example: The core doctrine of "temporal punishment due to sin" (i.e. purgatory) is still believed, but in practice, the V2 church no longer has requiem masses, nor encourages the faithful to pray for the dead.
2 of my novus ordo neighbors told me about some family members who had died and I offered to pray for their souls and started talking about purgatory. They quickly changed the subject and didn't want to be bothered about it. They still go to weekly church and are considered "good" catholics. It was very odd behavior for a catholic; but very typical for a novus ordo protestant...which is what they've been TRAINED TO BE.