Shad Revamp 65% Dodge?

Shield Mastery gives now 20% Avoid Rate.

Does that mean with Shadow Shifter they have 65% Avoid?

No. Shield Mastery gives avoid rate not doge rate. Paladin's Shield Mastery gives more 10% avoid rate(Guarding).

There is a difference between avoid and dodge.
Avoid is a stat on your stat menu that gives a chance to be missed depending on your avoid and the monster's accuracy.
Dodge is a passive rate that is independent of a monster's accuracy.

Above posts are right but also incorrect.

There's evaR%, which is just your avoid multiplied by said percentage. Mastery usually has this trait.
There's er% which is evasion rate%. This multiplies the avoid rate that is taken above from factoring the avoid equation in consideration with the monster's accuracy and multiplies it by said er%. For example, if you had 6000 avoid and the monster had 200 accuracy and this led you to have a 42% avoid rate and you had 15% er% then your total avoid rate would be 48%.
Then there's prop%, x% and any other variant of it. Which is just dodge chance. This is taken by having the hit rate and multiplied by your dodge rate.