No, Mr. Johnny come lately.
There were abuses in practice, NOT abuses in teaching.
Trent resolved the abuses and the teachings remained unchanged.
Thank you for playing.
https://en.wikipedia.org/wiki/Indulgence#Protestant_Reformation
Fortunately we have Colossians 2:13-14 to counter this false teaching of Roman Catholicism.
13When you were dead in your transgressions and the uncircumcision of your flesh, He made you alive together with Him, having forgiven us all our transgressions, 14having canceled out the certificate of debt consisting of decrees against us, which was hostile to us; and He has taken it out of the way, having nailed it to the cross.
Our sin debt was paid in full at the Cross. The Greek definitions behind this passage indicates our sins are wiped away...erased.
If the blood of Christ is insufficient to remove our sins then nothing mere man can do will.
The false notion of mortal sins causing one to lose salvation is again countered by Ephesians 1:13-14
13In Him, you also, after listening to the message of truth, the gospel of your salvationhaving also believed, you were sealed in Him with the Holy Spirit of promise, 14who is given as a pledge of our inheritance, with a view to the redemption of Gods own possession, to the praise of His glory.
We have nothing in the NT to ever indicate a believer can unseal what God has sealed...or that God unseals the believer.
A distinction without a difference.
The abuse of indulgences was endemic from the bottom to the top of the church structure. How is that NOT teaching?
Why is it so hard to say that they were wrong on selling indulgences without adding excuses?
When the PRACTICE does NOT match the TEACHING; where will you place the blame for it?