I’m going to get a lot of flak for this post.
I’m a loyal and orthodox Catholic, and I love God, the Pope, and our Lady. However, i’m not in favor of raising Co-Redemptrix and Mediatrix to a dogma.
Why? Because dogmas are articles to be believed about God. All four of the Marian dogmas share this common trait: They defend truths about Christ. Christ is fully God and fully man, hence Mary=Mother of God. Christ is God, and worthy of a pure vessel, hence Mary=Immaculate Conception. Jesus is King, therefore, Mary=Queen Mother=Assumption (Immaculately Conceived to, see above, therefore not subject to corruption). Where God enters, no one else will. Therefore Mary=Ever Virgin.
Now about Co-redemptrix and Mediatrix? These are truths about Mary, but what truth about God and Christ do these titles define? Okay, I can relax somewhat with the Mediatrix part (Christ=all grace), but the Co-redemptrix? Advocate? These are valid titles when understood correctly of our Lady. But what truth do they speak of God? What Christological fact do they teach? This is how previous Marian dogmas were defined. Always in terms of God and Christ.
I have no problem with the proper understanding of all these titles. But they tell more of her (SHE participated in a special way in Redemption; SHE intercedes for us; SHE bore Christ into the world) rather than of Christ (CHRIST is THEREFORE, Mary is . IMHO, let the teachings stand as they are until they are precisely defined as the previous four dogmas are.