CC Father has an excellent post on the subject here.
In it, he outlines his reservations as follows:
The first is that this seems to be a part of a pattern of post-hoc legitimisation of illegal behaviour. It is not as egregious as the legitimisation of altar girls. That was done by chicanery - at least this is a more official procedure. But the pattern endures - and the message it risks sending is simple. If you disagree with the Church's law, carry on - the Church will catch up with you eventually. That is clearly both wrong and dangerous.
The second is that it risks confirming a modern anthropological error: that male and female are trivial, not essential, differences. It risks appearing to bow at the altar of a modern understanding of what it means to be a woman (or a man); an understanding that sees contraception, promiscuity, and abortion as stepping stones along the road to true equality. The Church should be correcting this view, not colluding (or even seeming to collude) with it.
A third is that it risks colluding with another (related) error: that the Church has, by and large, got it wrong in the past, and needs to catch up with modern understandings in order to correct its practice and belief. I remain unconvinced that modern western liberal democracies have anything of significance to teach the Church. I would argue, rather, that there is a lot that they could learn from the Church, if only they would not harden their hearts.
My fourth concern is that it is premised on a wrong understanding of liturgy. It seems to be using the liturgy as a means of (at worst) 'virtue signalling'; or at best as a means of 'making everyone feel included.' I suggest that both of these fall far short of liturgy's true purpose. That is not to say that the liturgy of the Church cannot, or indeed should not, change. But, as Sacrosanctum Concilium rightly ruled, nothing should be changed unless the good of the Church certainly requires it.
Finally, the Decree says: 'In order that the full meaning of this rite might be expressed to those who participate it seemed good to the Supreme Pontiff Pope Francis to vary the norm...' I remain unconvinced that the Holy Father has explained the full meaning of this rite, which is rich and complex; and further unconvinced that it is better expressed by changing it from 12 men to a small group of people. The impression one gets is that the word 'seems' is carrying all the weight: Francis is not a theologian, and I think he should change the liturgy only with proper advice and theological consideration - or not at all.
Read the full article here.
I totally agree with everything he says here and it is a cause for great discomfort for me. I cannot help but feel that an important part of my faith is security in the knowledge that the Holy See and the Magisterium are guided by the Holy Spirit. My studies revealed to me a complex and careful working out of God's Revelation to man, but these days, I just don't understand a lot of what is going on.